My friend has an Xbox One and I have a laptop and I wanted to know if we can play GTA Online together when we both buy it from the Microsoft Store. In other games, such as Sea of Thieves, this is possible, for example, so the suspicion. Since I'm unsure I do not want to spend 30 euro, just to try it out. I would be very happy to receive an answer.
No is not possible. Is not a crossplay for GTA 5 and is not an Xbox Play Anywhere title.
No matter where you buy the game, you play it on the PC, there's no cross platform on GTA V. It does not matter where you redeemed the game key, but with which device you play.