Allow self-sign certificates or use the system ones, when using HTTPS proxy (transparent or not)

To connect to internet, I have a proxy to drop all the ads. It is a squid proxy. In case of HTTPS connection, il do ssl bump and generate a fake certificate, signed by a local Certificate Authority.
This local CA is installed in my system (Debian Buster).
Apparently, FreeTube don't use it and write "Self signed certificate in certificate chain"

I also try to use a proxy, but same issue as the certificate is unknown in FreeTube.

Could you use the system wide CA, or allow to specify a local one by using a startup parameter ?

Thanks
Dom