The other day I wanted to send someone proof that a transaction has gone through. A screenshot would have been the obvious choice, but of course, my banking app wouldn't let me do it.
A screenshot would also be trivial to counterfeit. That being said, I am not aware of any banks that provide any actually tamper-proof, shareable transaction confirmations.
I don't know about your bank/countries, but all of the banking apps in my country I've seen have 1. a "share account details" button that lets you easily paste your IBAN and other details in text form and 2. a "transaction receipt" button that saves a .pdf with the relevant details, that can be sent to the other part (although I agree with the other comment, this .pdf just like a screenshot can be easily spoofed)
