Far Cry 6 does not introduce anything new to Ubisoft games when it comes to microtransactions. Just like other games, it has microtransactions.
However, it is not at all necessary. You can buy a special in-game currency that you can spend on various cosmetics or weapons, as well as some unlockables that allow you to find some collectibles faster.
Related: Where to find all Criptograma Charts and Chests on Valle De Oro in Far Cry 6?
You can buy Far Cry Credits for real money ranging from 4.99$ up to 49.99$ packs of those credits. You can spend them in the in-game store to unlock some utility items like a Guide to Yara that unlocks most of the unlockables' locations.
In other sections, you can unlock some transport packs that include various vehicles, equipment packs with weapons and trinkets, bundles containing new cosmetics, vehicles, and everything else.
You do not have to spend any real money on microtransactions in Far Cry 6 to have fun. You can find everything without the special maps, and other than that, there are only cosmetic items at the moment.
For more articles and guides on Far Cry 6 make sure to check out Where to find all Criptograma Charts and Chests on Madrugada in Far Cry 6?