Can anyone help OBA28 error message when I try to link my bank account

Sending good vibes to you, @flintspetservice. I'll make that you'll be able to link your bank account in QuickBooks Online.
 

To get rid of the error code OBA28 and connect your bank successfully, you'll need to utilize the PINsentry token. 
 

If you still get the same error after using the PINsentry token, you can perform the basic troubleshooting steps. 
 

1. Log in to your QuickBooks Online account in an incognito or private browser.
2.  After logging in, go to the banking section, and link your bank account. If it's connected.
3. Go back to your regular browser and clear the cache. Clearing the cache resolves any common browser-related errors. 
4. Then, try connect again ang bank. 
    

You can also reach out to your bank for further assistance regarding this error. 
 

Let me know in the comment section if you need further assistance. I'll be around. Keep yourself safe and protected!