WHAT IS CHECKPOINT_REQUIRED ?! – Followers Track for Instagram! Review

I’ve used this app for few years now and I’ve not had a problem logging in for awhile, now it’s telling me something about “checkpoint required” and not allowing me to log into the app is it just my phone or app ?! It’s not showing or telling me anything besides that or further instructions on what to do.
Review by Jhay_lovee on Followers Track for Instagram!.