XBox Game Pass Ultimate can be canceled monthly?

At the moment the promotion is running that you can claim 3 months Discord Nitro with the XBox Game Pass Ultimate (https://support.discord.com/hc/en-us/articles/360047412672-Get-3-months-of-Nitro-with-Xbox-Game-Pass-Ultimate#h_01EGMG07Y34DMP0JNYSWTKFA3V) if you haven't had any Nitro yet. Now you could buy the Game Pass Ultimate for 1 euro, claim Discord Nitro and cancel your subscription, right? Or is there a minimum contract period (please refer to sources)

Yes, you can cancel immediately after completing the subscription.

Note, however, that you have to save a permanent payment option with the offer. That would be a credit card or PayPal.