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":
You should now see the mitmproxy certificate listed in the Authorities tab.