Hello.
From what we can see, it hasn't yet been activated on the new Mac. While Parallels Desktop subscription allows usage of Toolbox for its duration, it still has its own license key input interface, as you can also use it separately. It is most likely that the installation used a trial time as non-activated, and now wishes to acquire the license key.
Please try to activate Parallels Toolbox on your new Mac:
1. On your new Mac, click on the Parallels Toolbox icon in the Mac menu bar.
2. Click on the "Gear" icon in the top right corner.
3. Select "Account & License" -> Sign in to your account -> Input the license key or use "I have a key" button if necessary and use your Parallels subscription license
4. Check if you can activate Toolbox and if the pop-up alert disappears.
If the issue persists, please let us know, and send us a report after reproduction (Click on the Toolbox icon in the Mac menu bar -> Click on the "Gear" icon -> "Help" -> "Send technical Data") and send the report's 9-digit ID in a reply message.