There could be a few reasons why you couldn’t link your application.
No applications were found that match the information you provided
The information you enter to link an application must match the information you put on the application when you submitted it. If you updated your application after you submitted it, enter the most recent information.
You tried to link and application more than 5 times.
You can try to link an application 5 times. If it doesn’t work after 5 tries, you’ll be locked out for 24 hours.