How to transition to a backend engineer role from frontend

Hey folks, I am a senior software engineer at Swiggy working in as a mobile engineer for the past 5 years. I have worked on few backend & infra stack in past companies (node js, go-lang, kubernetes, s3, etc) just for exploring and expanding my horizon. I am thinking of seriously perusing this now.

What are my options here? I am open to learning via online course / my own side projects.

Also how to approach for hiring given it won’t be my expertise but I am willing to be hired at a lower package for the long term benefits.

Reason to consider a transition is boredom with working in a single domain.