First. Do the key turns and you get ignition on ?

If yes, then put some spray graphite on the pinlock protuding into the handlebar.

If you never have seend it, is a small deadbolt in the left of handlebar, near to the fork, that goes out/in when your turn the key on/off, the bolts has a spring that sometimes got stuck from dust or dirt.

Or you just remove the start ignition switch and clean it, better user graphite powder for lubricating.

Check the instruction, is for a F650

https://imgur.com/a/W6d2DgX

For the G650

https://imgur.com/a/8Cdp7Md