Ask HN: Switching to a Engineering Manager role from individual contributor role

I have been an individual contributor in small teams across startups so-far. I have played multiple pivotal roles as an individual contributor while also acting as a mentoring manager. However , i would like to switch to a full-time engineering manager role with my effective senior developer skills. I am presently a senior developer with SaaS company , having worked in the industry for close to 7.x years . How do i switch to a full engineering manager role ?Most places seem to require prior experience but how does one bootstrap?