The "LR" button is missing in YouTuve

Somehow, my “LR” button on YouTube video player is missing:

How to get the button back?

(After re-installing the LR, the button still did not show)

Hey there,

Please make sure you don’t have a domain blocker (e.g. if on a corporate network)
Please make sure all necessary permissions are granted:
Open Chrome menu > More tools > Extensions > Language Reactor > Details
Scroll down to ‘Permissions’ and make sure all switches are on.

Let me know if it didn’t work.
Hofit, LR team