How can I add a checking account from a bank that doesn’t offer online banking

I can help you with this, lawmiller-mail-c.

For a bank that doesn't offer online banking, you can it to your Chart of Accounts in QuickBooks Online. Let me guide you how:

1. Go to Settings and select Chart of Accounts.
2. Select New.
3. Choose an account type, in the Account Type dropdown.
4. In the Detail Type, choose the detail type that best fits the transactions you want to track.
5. Enter the account name. 
6. Select Save and Close.

You can learn more about the process in this article: Add an account to your chart of accounts in QuickBooks Online.

You can also manually import transactions to your QuickBooks Online account. I'll show you how:

1. Select Banking from the sidebar menu, then click the Banking tab.
2. Hit the Upload transactions button.
3. Click Browse, then choose the file you downloaded from your bank.
4. Select the account you want to upload the transactions into from the QuickBooks account ▼ drop-down menu, then select Next. 
5. Follow the on-screen instructions, then click Next.
6. When you’re ready, hit Let's go.

Once transactions are added in QBO, you match and categorize them.

I'll be right here to keep helping if you have any other concerns or questions about banking.