Sure, in sequence:
ran this:
plesk bin http3_pref --disable -panel
and
plesk bin http3_pref --enable -nginx
to enable HTTP/3 only for websites, not Plesk panel
plesk bin server_pref -u -ssl-protocols 'TLSv1.2 TLSv1.3'
to install TLS
nginx -t
to check config and then
plesk bin...