Back Panel Came off..

I got zero idea on how to fix this now. Help. I just opened by spigen back case to clean this came off along with it

https://preview.redd.it/6u8yzc71dwkc1.jpg?width=2304&format=pjpg&auto=webp&s=659fec262d4b29118d4edb96aa8ad2f991a01ce0