Deploy ammo crate

[HandsInTheZverák]

Hello, my quest is asking for deploying ammo crates for team mates. Searched reddit and found a tread where hes told to press 6 to deploy ammo create. But when I press 6 I hold yellow box in my hands that cant be deployed
Please help

[Keys]

You need to be playing support and change their gadget to Ammo Crate to be able to deploy one. They normally have like a Med Crate or something. For me it's 4 but I'm not sure if that's the default cause I changed my keybinds. What you're pressing is the building tool which displays as a yellow box.