How to get an expense on the bank register so i can reconcile my bank account. for some reason the expense did not download from the online bank information?

I can help you with that, diane93.

By default, your financial institution controls what and how information is received by QuickBooks Online. Since the expense transaction wasn't downloaded, you can manually upload your bank transactions to your QuickBooks account.

You can start by signing in to your bank's website and follow the instructions on how to download them. Currently, these are our supported file formats:
 

• Comma-Separated Values (CSV)
• QuickBooks Online (QBO)
• Quicken (QFX)

When you're ready, here's how to upload the file:
 

1. Select Banking or Transactions from the sidebar menu, then go to the Banking tab.
2. Choose the blue tile for the account you want to upload the transactions into.
3. Click the Link account drop-down menu, then select Upload from file.
4. Hit Browse and select the file you downloaded from your bank. Then, select Next.
5. In the QuickBooks account drop-down menu, choose the account you want to upload the transactions into. 
6. Click Next, then follow the onscreen steps to match the columns on the file with the correct fields in QuickBooks.
7. Select Let's go to complete the process.

Once done, go back to the Banking menu to match and categorize the expense transaction. Once done, you can now reconcile your accounts to ensure that they always match your bank statements.

I'll be right here to continue helping if you have any other questions or concerns. Have a great rest of the day.