Being a newbie who doesn't know how this process works, it is necessary for me to ask these questions;

If I (or you) were to sell the concept of a pop-up optin form on a client' website, what would the process of installing the form look like?

Is this a task for a developer, or could a person with limited coding and some WP blog building skills complete it?

If this is a coder task, how would they get access to the site in order to add the optin form?

Lots of details need to be ironed out.

Thank you for any and all replies.