Selfhosted ios certificate problem

Happy New Year everyone,
I want to change my password manager to Bitwarden and I have provided Bitwarden via Proxmox.

The server and therefore the webgui listens on Now I installed the Bitwarden iOS app and wanted to connect to the server locally (I have a permanent VPN connection to home with my mobile anyway, so a DynDns or similar is not needed to access Bitwarden).

Unfortunately I get the following error message: “An error has occurred. Exeption Message: The certificate for this server is invalid. You may be connecting to a server pretending to be “” and compromising confidential data.”

I did a little googling and saw that you have to install the self signed certificate in iOS. My problem is that I don’t really know how. I downloaded the certificate and installed it in iOS. Unfortunately without success. In the certificate is my DynDNS name, because I had to enter a domain during installation and an IP does not work.

Hope Someone can help me?

Thanks in advance!