If you have created an add-on or extension for your organization, you can configure Firefox ESR to run it without having to sign the extension:
- Enter about:config in your address bar, and continue to the list of preferences.
- Find the xpinstall.signatures.required preference and set it to false.
Other installations of Firefox (non-ESR)
Mozilla also offers an alternative signing method using the web-ext command if you plan to self-host an add-on.