Can't link my bank account to the app

I see that you are experiencing difficulty in connecting your bank account to the QuickBooks Online app. You have arrived at the correct forum where I can assist you. I'll impart insight and guidelines to help you connect your bank account to QuickBooks.

If you want to connect your bank account to QuickBooks, you can do so through a mobile web or any available browser rather than within the app. If you use an iPhone, access it through Safari and Chrome or other available mobile browsers for Android. You can go directly to this link and log in using the same credentials: https://quickbooks.intuit.com/uk/login/

Here's an article that can guide you further in customising your invoice template and sales form delivery method on the mobile app: Customise invoices on the QuickBooks Online mobile app. 

For additional questions about linking your bank account or any QuickBooks-related concerns, don't hesitate to post them here in the Community. We're always available and willing to lend a hand to your queries. Have a great day ahead.