Problem is, DKMS install seems to succeed and adapter seen (according to lspci and dmesg) no entry for this adapter shows up in 'ip link'.
I also tried the rtl88xxau-aircrack-dkms-git driver.  Same results.
On same computer I have had USB eth devices and (slow) PCI wireless adapters successfully show up in 'ip link' and work.

USB Adapter: ANEWISH model XHT-6B12
https://www.amazon.com/gp/product/B07D2YDYPF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
I bought this one because it's supposed to have the RTL8812AU chip set and reviewers say it works with RTL8812AU Linux driver.

No problem with the physical adapter because it works great when I boot same computer into Windows.
Windows reports it as "Realtek 8812BU", reports events for Device USB\VID_0BDA&PID_B812\123456, and uses Realtek drivers rtwlanu.sys and wifibus.sys.

This DMKS module installed:
beyla# dkms status
rtl8812au, 5.6.4.2.r11.g3110ad6, 5.7.10-arch1-1, x86_64: installed
beyla# dkms status
rtl8812au, 5.6.4.2.r11.g3110ad6, 5.7.10-arch1-1, x86_64: installed

Traditional module 'rtl8812au' not present:
beyla# modprobe rtl8812au
modprobe: FATAL: Module rtl8812au not found in directory /lib/modules/5.7.10-arch1-1
beyla# ls /lib/modules
5.7.10-arch1-1
beyla# ls /lib/modules/*
build              modules.builtin.alias.bin  modules.devname      pkgbase
kernel             modules.builtin.bin        modules.order        vmlinuz
modules.alias      modules.builtin.modinfo    modules.softdep
modules.alias.bin  modules.dep                modules.symbols
modules.builtin    modules.dep.bin            modules.symbols.bin
beyla# 



Relevant section of 'lsusb -v':
--------------------------------------------------------------------
Bus 001 Device 002: ID 0bda:b812 Realtek Semiconductor Corp. USB3.0 802.11ac 1200M Adapter
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.10
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x0bda Realtek Semiconductor Corp.
  idProduct          0xb812 
  bcdDevice            2.10
  iManufacturer           1 Realtek
  iProduct                2 USB3.0 802.11ac 1200M Adapter
  iSerial                 3 123456
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0035
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           5
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass    255 Vendor Specific Subclass
      bInterfaceProtocol    255 Vendor Specific Protocol
      iInterface              2 USB3.0 802.11ac 1200M Adapter
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x84  EP 4 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x05  EP 5 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x06  EP 6 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x87  EP 7 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               3
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x08  EP 8 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
Binary Object Store Descriptor:
  bLength                 5
  bDescriptorType        15
  wTotalLength       0x0016
  bNumDeviceCaps          2
  USB 2.0 Extension Device Capability:
    bLength                 7
    bDescriptorType        16
    bDevCapabilityType      2
    bmAttributes   0x00000002
      HIRD Link Power Management (LPM) Supported
  SuperSpeed USB Device Capability:
    bLength                10
    bDescriptorType        16
    bDevCapabilityType      3
    bmAttributes         0x00
    wSpeedsSupported   0x0006
      Device can operate at Full Speed (12Mbps)
      Device can operate at High Speed (480Mbps)
    bFunctionalitySupport   1
      Lowest fully-functional device speed is Full Speed (12Mbps)
    bU1DevExitLat          10 micro seconds
    bU2DevExitLat        1023 micro seconds
Device Status:     0x0000
  (Bus Powered)
--------------------------------------------------------------------

Relevant dmesg output:
--------------------------------------------------------------------
[    1.606531] usb 2-1: New USB device found, idVendor=0bda, idProduct=b812, bcdDevice= 2.10
[    1.606533] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    1.606534] usb 2-1: Product: USB3.0 802.11ac 1200M Adapter
[    1.606535] usb 2-1: Manufacturer: Realtek
[    1.606535] usb 2-1: SerialNumber: 123456
--------------------------------------------------------------------