AK5C I can't unlock it!!!

Hi, I'm back on battlefield 2042 just to try to unlock some content for battlefield 6.

I would like to play with the ak5c in the meantime and I have already done the 50 kills at 50m range.

However, I cannot find on any weapon the shotgun to attach to the underbarrel. I read somewhere that they have been disabled? Is that true? I tried using the pellet grenade launcher but it doesn't work!
How do I solve this?