You'll want to login to your UKG Pro account and search Service Account Administration.
Paste the Customer API Key in Merge Link and click Submit.
Click on + add.
Enter in a new user name and email.
Scroll down under Web Service and enable all relevant permissions. Note that Employee Person Details is a minimum requirement. Other relevant permissions include PTO Plan Integration, Company Configuration Integration, Payroll Integration, Personnel Integration, Employee Job History Details, Employee Person Details, Employee Compensation Details.
Click Save. Your new password will pop up. Save the password in a secure location and copy both the user name and password into Merge Link!
Enter your UKG Pro credentials in Merge Link and click Submit.
Navigate to Security > Web Services.
Copy the subdomain from the endpoints URL up until you see "ultipro". For example if your URL is, http://Servicet.ultipro.com/services/BIDataService then type in "Servicet" into Merge Link. Click Submit and you should be all set!