Can anyone tell me how long it takes for a vendor payment to show up in my account?

Welcome to the Community, @bugifer.

Let me share information on how long it takes for a vendor payment to show up in your account in QuickBooks Online (QBO).

If you're a new user of QuickBooks Payments, your initial set of payments will be deposited within 5 business days. These early deposits may take a little longer as we work on setting up your account. However, once everything is set up, customer payments will be deposited much faster.

Additionally, if you process customer payments before 3 PM PT, we'll deposit them in your bank account on the next business day. For payments processed after 3 PM PT, we'll deposit them in your bank account in two business days.

You can check this article for more detailed information on how long it takes to get customer payments in your bank account: Find out when QuickBooks Payments deposits customers' payments.

I will also include a helpful article that guides you through the process of running a report: Run reports in QuickBooks Online.

Please let me know if you have further concerns about payments. I’ll be right here with you.