PC: How do I actually use my grenade launcher?

[zerosleep]

Stupid question of the day. I'm looking at the mappings and I don't see an obvious way to use/re-map the optional grenade launcher on some weapons. I'd love to just press one of my side buttons and use it on demand.

[你没有朋友]

You need to aim then hit V, go Into key mapping and it's under weapons (I think, can't remember off the top.of.my.head) it's at the bottom, called underbarrel attachment I think