Unable to use wifi on my TP-Link dongle with the RTL8812AU chipset

Hi ! I am unable to use my wifi dongle. I tried this post -

but after running the sudo make dkms_install command, i get this error -
mkdir: created directory ‘/usr/src/8812au-5.6.4.2_35491.20191025’
cp -r * /usr/src/8812au-5.6.4.2_35491.20191025
dkms add -m 8812au -v 5.6.4.2_35491.20191025
Creating symlink /var/lib/dkms/8812au/5.6.4.2_35491.20191025/source → /usr/src/8812au-5.6.4.2_35491.20191025
dkms build -m 8812au -v 5.6.4.2_35491.20191025
Error! Your kernel headers for kernel 5.14.10-300.fc35.x86_64 cannot be found at /lib/modules/5.14.10-300.fc35.x86_64/build or /lib/modules/5.14.10-300.fc35.x86_64/source.
Please install the linux-headers-5.14.10-300.fc35.x86_64 package or use the --kernelsourcedir option to tell DKMS where it’s located.
make: *** [Makefile:2304: dkms_install] Error 1

Any help will be appreciated !

Try the instructions in this previous item regarding installing kernel headers: https://discussion.fedoraproject.org/t/where-to-get-kernel-headers-5-15-11-200-fc35-x86-64/72958

You need to install the following, as well as do a full upgrade before you do the builds.
sudo dnf install kernel-devel kernel-headers and sudo dnf upgrade
After doing those 2 steps the build should work for you.