Hi @Ludo everything in that Getting Started guide references an older image with a highly tweaked v4.14.x/v4.19.x kernel image.
All that stuff hasn’t been re-ported to v5.10.x yet…
Feel free to use the TIDL specific 10.x (buster) Snapshots: Debian 10.x (Buster) - Monthly Snapshots
Which are also updated once a month…
Regards,