I can walk you through the process in linking your bank, abbyco.
We can connect it in the Banking tab.
- On the Banking tab, click Connect account.
- Search your bank, then enter your login credentials.
- Click Continue.
- Select the type of account you'd like to link. Hit Connect.

Once connected, QuickBooks will automatically download your transactions. You can also update your login credentials if you changed it on your bank's website. Just click on the pencil icon and select Edit sign-in info.
In addition, you can read this article if bank transactions won’t download. It will give you the steps on how to resolve banking errors.
I'll be right here if you need my help. Have a great day!