Out of curiousity, what makes you think you "only got the job" because of the title on LinkedIn?

Did you consider that the company hiring maybe saw potential in you? Or maybe even existing ability that you don't recognise (our industry is rife with impostor syndrome)?

Perhaps they realised you wouldn't be a lead dev but had you earmarked for a more junior role.

My basic point is: be optimistic and courageous. The worst case scenario is you learn something. If there's one thing I've learnt recently it's that no one will hold anything against you for taking a leap of faith.