I created a new certificate via uHTTPd and am struggling with trusting the certificate considering that Firefox gives an error about ownership.
Here's the error message: This personal certificate can't be installed because you do not own the corresponding private key which was created when the certificate was requested.
You need to add it under Servers. Simply add, enter your HTTPS URL and the browser saves/pins the cert automatically for that domain name.
Take note: Do not enable Data - Site Preferences under History - Clear Recent History if you use that functionality. It will also remove all the cert overrides you add here. Annoying but not the end of the world.