Bitwarden App login failure

Hello,

I installed vaultwarden in Home Assistant. Everything works great and I can access vaultwarden on the go via VPN. The only problem is that I can’t log in with the Bitwarden app, not even in the local network. I always get the error message: Exception message Connection failure. I’ve read that it’s probably due to the SSL certificate. But I’ve created one and it’s in the SSL folder. How can I solve the problem? It would be enough for me if I could only log in locally in my network to the app. I don’t want to open any ports to the outside, I just want to use VPN. Please Help me