Hello @WolfgagnF5
Thank you for reaching out to Parallels.
You can upgrade from Parallels Desktop 15 to Parallels Desktop 18 and it will work with the M2 processors.
To purchase an upgrade license, please follow the link: https://www.parallels.com/desktop-upgrade/
For more information on Parallels Desktop upgrade, please go to the following link https://kb.parallels.com/en/124250
Thanks