Not Able To Access Free Chegg Answers For Chegg Premium Account

Hey Guys, I'm a new iPhone user and I'm using iPhone XR 64GB, And I'm a college student and using Chegg to solving my answers, I randomly search on google FREE Chegg answers and got many results, One of them is FREE Chegg answers by tricks wire. It's genuine he is providing answers for Chegg.

So my question is my every apple iPhone user friends are able to use Chegg answers for free on their devices. But I am not able to use these accounts on iPhone XR.

I need your help guys to solve this issue with my device, Thanks.