Trending @Infosys; How to switch to be a Backend dev ?

One way if your current project has backend stories then pick them up. Second way is to skill up, do so by courses and certifications let the manager know about your interest so he/she can maybe change to a project where they need backend devs. If both didn't work then do some practice with side projects and get an offer outside for the backend role, while putting papers explain to them I am shifting for a backend role then maybe they offer you a backend role here, then you decide whether to shift or stay here.