While you're busy killing Nazis in co-op FPS Wolfenstein: Youngblood, you can collect coins from the environment which you can then spend on weapon skins, cosmetics and emotes. You'll also be able to spend real-world money on gold bars which can be exchanged for those coins. But contrary to some reports this week, you won't be able to buy in-game weapon upgrades that way.
According to a Bethesda comment in this VG247 interview with MachineGames, only cosmetics will be purchasable. Originally, it seemed a Wolfenstein: Youngblood developer had said during an E3 roundtable that weapon upgrades would also be purchasable, speeding up gameplay progression.
"Bethesda has confirmed to VG247 you won’t be able to upgrade weapons via microtransactions in Wolfenstein: Youngblood," the update reads. "It’s only cosmetic weapon skins that can be bought using microtransactions in the game."