which field? do you have a screenshot?
On desktop, I click on "open wallet" under the QR code, and it takes me to the approve payment, and I can't change the amount. https://image.nostr.build/dd605b12fe9d7a4cef7f6b8ff595752a596f2118bcb99400bf67c4c86c841cb2.png
Also, if I put in a budget for "one-click" payments in settings, I get a "bad arguments, error 404" message.