How do I approach this situation

I want to work in a department (sorta legal) in a consultancy firm. Recently I connected with senior manager in that particular department. I did not text them yet. I desperately need to join that team for my career growth. How do I approach them. Should I text hr first or the senior manager? I'm a fresher and new to applying jobs. Suggest the best way to approach them and ask for a position in their team. Thank you