How to install the __mitmproxy__ certificate authority in Firefox:

1. If needed, copy the ~/.mitmproxy/mitmproxy-ca-cert.pem file to the target.
2. Open preferences, click on "Advanced", then select"Encryption":
3. Click "View Certificates", "Import", and select the certificate file:
4. Tick "Trust this CS to identify web sites", and click "Ok":
5. You should now see the mitmproxy certificate listed in the Authorities tab.