Then you are going to have to provide more information as when it is lacking all that can be done is guess which leads to the post provided by SravanKrA when this link is due to using Sign in with Apple.
I can provide another guess and assume you are talking about downloading an app withe a different Apple ID and now when logging in with a another Apple ID, the app cannot be updated without the Apple credentials used for the downloaded app. If this is what you are experiencing, then you will need to delete the app and download it again with your current Apple ID. Any data stored with the app will be lost and you cannot unlink an app from the Apple ID used to download it.
It is also unclear when you say nothing happens after clicking the delete button. You can provide a screenshot as long as it does not contain any personal information if that would help visualize what you are seeing.
You incorrectly assumed that SravanKrA was a bot, so you can see how these kind of assumptions often lead to unhelpful responses when a lack of information is provided. If you are using a VPN and Sign in with Apple, then you are likely going to get unexpected results.