React.js mobile view, focus is moving outside the modal after the last modal element and it's focusing on a parent element when using Google TalkBack

Question

I have react JS web application with mobile view also. When i clicked on a button called view coupon focus is start working from Close button and end on Condition text but after this last element in modal box focus countinue to focus on parent page. We have to trap focus inside the modal box for mobile view and desktop view. curretly it is working on desktop view.

Need solution for above accessiblity issue