Do you have a subscription created outside of Wix with a third-party? Unfortunately, it is not possible to use this subscription to upgrade an app from the Wix App Market.
For example, if you have an account with 123 Contact Forms that you created outside of Wix, you cannot use that account to upgrade the 123 Contact Forms app on your Wix site.
Tip:
We suggest you contact the third-party app provider directly to see if they can provide assistance.
This article is credited to the Wix team - https://support.wix.com/ and we thank them for that!