"Your current licence does not include the use of the EA Designer."
The SquaredUp licence currently being used is not a product edition that includes use of the Enterprise Application (EA) Designer.
To check the product edition of the licence being used see How to check which licence key is being used. To see what is included in different product edition licences see the Licensing Overview.
The EA Designer is included in the Enterprise Application Monitoring (EAM) edition. If you have the Essentials or Enterprise edition and wish to upgrade please contact email@example.com
If you have recently upgraded your licence you may need to reactivate the licence for SquaredUp to pick up the recently added features. See How to reactivate your licence.