• You are using SharePoint online (Office 365) environment

Step 1: Open Classic features on SharePoint admin portal 

Replace the YourTennantName in the following url with the name of you SharePoint online environment and open it in a browser.

Click on Classic features on the left menu section:

Step 2: Click on Open button under User profiles section

Step 3: Сlick on Manage User Properties under People section  

Step 4: Click on a New property

Step 5: Fill Name and Display Name for new user profile property

Step 6: Click OK button

Scroll down the page and click on OK button to create a property

NEXT: Connect ShortPoint with Custom User Profile Property Using People Search Connection