Using self signed certificates / unspecific error message on setup [SOLVED]

Some of you might get an unmeaning error message on setting up filelink that there was an error. For me i figured it out after some (acutally a lot of) googling:

When using a self-signed certificate you will get this error message. You have to add the certificate to the exceptions. Go to Setttings --> Advanced --> Certificates --> Manage Certificates --> Server and add your server there. Note that your local IP https://192.168.178.xyz and https://my-nextcloud.no-ip.org are not the same. Add the one you will use for filelink. Only the latter makes sense unless you’re only sending emails within your private network.

May I suggest the authors of this marvellous plugin to add this note in the installation instructions or even improve the plugin that you can grant the exception within the setup process?

Since the last bounty 28 days ago, nobody cared about the plugin. I think smb. need again to place 200 USD. It’s sadly…

Sorry, but i had the same problem.
I have to support the ask for a notice about self-signed certificate in install-instructions.