The FedEx shipping options are showing on checkout. The only problem now is the create shipment feature

Customer :

The FedEx shipping options are showing on checkout. The only problem now is the create shipment feature.”This is a production key” box is checked.

Here’s the error message:
Fedex Create Shipment Error: Severity: ERROR
Source: prof
Code: 1000
Message: Authentication Failed.

Support :

You need authorization from FedEx while printing label in production mode, that’s why you are getting this error

You need to contact FedEx with the sample label generated using Test Account details