OpenWrt Kernel Issues for Camera and USB Wifi Stick

1.I am getting Error as follows.

The installed version of package kernel is not compatible, require 5.4.87-1-d860abdf… while 5.4.87-1-48bd3fe8… is installed.

Do I have to upgrade or downgrade the kernel. How Do I change my kernel to required kernel version.

  1. I have two systems: on two RPI 3B+ sd cards . I am getting errors
Linux OpenWrt 4.14.180 #0 SMP Sat May 16 18:32:20 2020 aarch64 GNU/Linux
Linux OpenWrt 5.4.87 #0 SMP Thu Jan 14 13:06:00 2021 aarch64 GNU/Linux

But No USB Stick for wifi 802.11ac is detected. I cannot do make as per

git clone
cd rtw88
make -C /lib/modules/5.4.87/build M=/root/rtw88 modules
make[1]: *** /lib/modules/5.4.87/build: No such file or directory.  Stop.
make: *** [Makefile:79: all] Error 2

I have the following output:

       0bda:b812 Realtek Semiconductor Corp. 
Fri Jan 15 06:51:09 2021 kernel: [  297.032612] usb 1-1.3: new high-speed USB device number 7 using dwc_otg
Fri Jan 15 06:51:09 2021 kernel: [  297.163794] usb 1-1.3: New USB device found, idVendor=0bda, idProduct=b812
Fri Jan 15 06:51:09 2021 kernel: [  297.172381] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Fri Jan 15 06:51:09 2021 kernel: [  297.181427] usb 1-1.3: Product: 802.11ac NIC
Fri Jan 15 06:51:09 2021 kernel: [  297.187386] usb 1-1.3: Manufacturer: Realtek
Fri Jan 15 06:51:09 2021 kernel: [  297.193312] usb 1-1.3: SerialNumber: 123456

No video detected. Camera is installed on RPI 3B+ camera port.

root@OpenWrt:~# v4l2-ctl --list-devices
Cannot open device /dev/video0, exiting.

I am new to OpenWrt. I installed the OS Linux OpenWrt 4.14.180 from source downloaded image. Second Image I build on Debian (Ubuntu 18.04) Desktop.
I really need to get the USB Wifi Working on 802.11AC and the camera working.