Thank you for sharing this information. Living in an imperialist country makes it hard to understand China’s politics and not fall into some of the propaganda against it, even if you’re careful.

You can either install it unsigned with Firefox Developer Edition and it will be permanent. Or you can sign it yourself (you don’t need to publish it on AMO): https://extensionworkshop.com/documentation/publish/signing-and-distribution-overview/ and it will work on regular Firefox.

You can build it yourself from source then.

So you proved yourself wrong. Congrats.