[Mashiro]

Oh it works all right. The provider is just using a self signed certificate for it. Do you know what self signed (SSL) certificates are? It is a certificate that was created locally on the server and has been signed by the server instead of a Certificate Authority like Let's Encrypt or similar.

These self signed certificates aren't less secure than those that are signed by trusted certificate authorities. The only difference is that browsers don't 'trust' self signed certificates and show such kind of error pagee. The encryption of traffic however is fully intact and working.

So untick the "Warn me every time" option and continue on.