Serious advice needed

So I am from a non tech background guy with 2YOE in mobile app development. When I started Mobile app dev that time I found it interesting but now it’s getting boring and the work is sort of monotonous. I want to shift to backend or maybe more towards software development. I asked my manager for switching my team but he doesn’t want me to leave the team. I tried applying else where but obviously I had no luck. Any suggestion on how I can make this transition? I’m desperately looking for helpful advices/ suggestions.