I dont think development is a good option for you depending on age. Do you really still want to be learning your trade at 45/50?
IT manager to techie is the reverse of what most people do, and then you often find great technical people are not always great managers, and vice versa. Understand what you are getting into, software development is much more than just code and can take a good few years to become truly experienced, learning the code, patterns, best practices takes time and youll be competing with kids fresh out of uni for trainee roles; those kids will also have a years experience from sandwich courses so will be at an advantage.
Play on your management experience and existing skills, look for roles like release manager, and possibly take ITIL exams. It could also be advantagous to look for IT jobs in a business similar to your current employer and aim to become a business analyst, project manager, or other “soft” technical role rather than the full on tech side.