Create the base of a web service (SAS) Codeigniter

Good day. I need the base for a web appplication I'll develop as a web service (SAS - Software as a service). Please only bid if you have experience in the following: CodeIgniter and SAS What I need: - Registration, Login, Logout, creation of access for the main user, the users can create subaccounts who will use the service, the service that you will apply is the creation of a simple bill that will be returned in PDF and the data included to it saved to a database. I'm hoping to chat with an experienced freelancer, I'll be awaiting for your proposals. Greetings!