Help with privacy related data for my business

Hello Everyone,

I am starting my new business which will provide webapplication tool to barbers. Barbers can use this tool to create hairstyle preview of their clients. Since barbers are taking the picture of their clients, Would I be needed any kind of consent flow in my application logic which records that barbers took the permission of their client before uploading their picture? if yes, can someone help me with what should be the language of that consent flow and what I should store? I am in MVP and going for Pilot testing, so my goal is to save money where I can. Any help or reference would be helpful.