Apple developer certifications?

Question

Apple Developer Program

I ask for your help, because everything has been tried ... There is such a site https://tadapp.ru (it makes it possible to create assemblies from a ready-made site into applications for apple and android. There are no questions with android ... For iOS, it asks for the keys of the pem support profile file and the file distribution certificate p12.I have a developer ID developer, macbook ... Please describe how to get them ... I have already tried all the options for creating keys and nothing works