Radxa repositories

Can’t get acces to http://apt.radxa.com/bullseye-stable/
and http://apt.radxa.com/bullseye-testing/ with synaptic.
Is there a new repository ? And key ?
Who can help ?
regards
Uli

Please check here: https://wiki.radxa.com/Rock4/FAQs#Radxa_APT_public_key_is_not_available