Welcome to the Community. I'd be more than happy to help you transfer money from your QuickBooks Checking account to your regular Credit Union account.
All you need to do is a few easy steps within your QuickBooks Online to transfer money out of your QuickBooks Checking account. Here's how:
Hit Transfer money and then Move money between your account.
Enter the amount to move from your QuickBooks Checking account.
Choose your QuickBooks Checking in the "From" field.
Select the Credit Union account in the "To" field by click the (+) button.
Tap Finalize transfer when ready.
If you're unable to see your Credit Union account or the transfer is not successful, I recommend reviewing your setup and ensuring it's correct with this guide: Use your QuickBooks Checking account.
If you have any trouble along the way, don't hesitate to let me know. I'm only a comment away if you need me. Best wishes!