The Check-in button appears once you lead a goal (Key Result, Initiative, or KPI). You will then be asked to update any goal(s) you lead via Check-in.
To see if you lead any goals, go to your Home page. Under My goals, there should be Key Results, Initiatives, or KPIs listed if you're the lead. Otherwise, no goals will be shown:
Need a hand? Contact our friendly Support team via the in-app chat at the bottom-right of your screen, or email firstname.lastname@example.org.