Assault Class, Breacher-extra grenade/not equping

Hello, does any body know how to use your second grenade as ASSAULT Class Breacher, iam lv 3 on PS5, it doesn't update to second grenade during a match. It shows the grenade symbol on the right hand side of the screen but I don't know how to activate it. L1 is standard button  for throws and grenades. It only works for the initial grenade per round and I can't activate the second grenade.