If you're having trouble with the app @oneielai see below. If the problem is an error trying to pay you'll have to be more specific about what's happening.
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For iOS 16 or later and Android 10 or later, follow the instructions here: How to update your eBay app
For older systems running iOS 15 or Android 9 or earlier, you can access eBay from a web browser on your device. Delete the eBay app so links open in your browser instead of the app.
Read more about OS compatibility updates: eBay UK Announcement
