Why the heck i cant add to Firefox

I wrote a script and it just f*cking won't work.
I scavenged the whole help page and nothing f*cking helped.
I copied the whole script and threw it to the developer console. It f*cking works.

This add-on is a joke.

I can't add tempermonkey to Firefox

为什么我的添加到Firefox点不了

unable to browse with newest version Tampermonkey

the newest version breaks the browser from starting

Close source since 2018

always opens new tabs itself on all PCs when it makes updates

not open source, maybe it sends all your data to china?