Prerequisites

• You are using SharePoint online (Office 365) environment
• You have admin access on your tenant 

Step 1: Open User Profiles

Replace the YourTenantName in the following url https://YourTenantName-admin.sharepoint.com with the name of your SharePoint online environment and open it in the browser. 

In the left-side menu, choose More features, then in the central part of the screen click User Profiles.

Step 2: Сlick Manage User Properties under People section  

Step 3: Click New property

Step 4: Fill in the Name and Display Name for new user profile property

Step 5: 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