https://github.com/fastoe/RTL8812BU 久沒更新，在 5.10 核心無法編譯。
https://github.com/cilynx/rtl88x2bu 有更新到 linux 5.10 可用。
As https://github.com/cilynx/rtl88x2bu/blob/5.6.1_30362.20181109_COEX20180928-6a6a/README.md says:
cd rtl88x2bu
VER=$(sed -n 's/\PACKAGE_VERSION="\(.*\)"/\1/p' dkms.conf)
sudo rsync -rvhP ./ /usr/src/rtl88x2bu-${VER}
sudo dkms add -m rtl88x2bu -v ${VER}
sudo dkms build -m rtl88x2bu -v ${VER}
sudo dkms install -m rtl88x2bu -v ${VER}
sudo modprobe 88x2bu
That's OK.
https://github.com/morrownr/88x2bu 近期還有更新，