I am working on a PHP program that does some tasks and then generates a text, this text must be able to be published later in a Wordpress (.org).
The Wordpress sites where it will publish are not mine and are not on my server so include wp-load or similar will not to work, for this, I will have in my database the login information (URL of the site, user, password).
I need to know how to connect from PHP and create the session in Wordpress. After that, I need to get the list of categories of the blog and then publish the generated text in one of them. Can it be done directly or do I need to make a plugin for this? I don't have experience making plugins and wordpress Rest API, so if there is a direct way it would be better.