That is becasue the issue isn’t Blynk related… every camera has specific layouts of allowed secure direct connection (NOTE: different from browser connection)… for example one of mine needs this
http://user:pass@xxx.xxx.xxx.xxx:pppp/mjpeg.cgi <— this last part is also completely dependent on the cameras internal server
While another might want it something like this
http://xxx.xxx.xxx.xxx:pppp/?user=username&pw=password
Basicly trial, google, error, repeat again, not a Blynk specific issue, so not much more the docs can help except to show that is is no longer limited to RTSP