If you can't find the key, about the only alternative is to buy a new ignition lock.
Hopefully, you didn't lock the fork lock.
The keys for my 2011 G5 have a number marked on them but looking at the ignition and steering lock on my motorcycle didn't show a number. At least, show it in a place that was easily seen.
Another option would be to just replace the switch with a standard, 2 pole switch.
There appears to be just a RED (power) wire coming from the batteries 20 amp in line fuse and a RED/WHITE wire(s) going to everything else on the bike.
Of course, any idiot could figure out what that switch was for.