How to allow the use of extensions for chrome downloaded not from the Google store?

Question

Google Chrome

Hello!
I have my own chrome extension already packed in crx. On my 2 devices, laptop (OS X) and PC (Win7), if you check the developer mode, everything is installed and everything works, then if you restart Chrome, a window pops up in which you can either disable extensions not from the store, or leave them to work. But on my friend's PC, after restarting chrome, in this window the button to leave the extensions is not active, and it turns out that after restarting chrome there are extensions, but it can't be enabled. Please tell me how to turn it on

Answer 1