I like to think that Tony make those suits with Scott after hearing about how captain marvel got her powers

because we learn that the space stone power Can get absorbed/copied into a organic lifeform

so going with that he and Scott get to work on them so they can absorb/copy to those little [quantum disks] < working title

But the way they collect the energy/power is though taking body shots the avengers take during the time when they come in contact with them in the past

So when they are all charge up they glow blue can use the power they absorbed

And with that leak that Tony builds his own gauntlet he take those [quantum disks] and puts them on it