SAAS app writes blog posts and post to WordPress websites

Please help me, is there a plugin or API that I can use for this task?

My SAAS creates SEO blog posts for the users, now they can can copy-paste the articles.

Is it possible? They install a plugin on their WP website, connects to my app and after blog post generation they just 1 clik and post the post?

I’m sure plugin can be developed. Does Wordpress have API integration module?!

If yes, I’m sure you can simply send data using API Connector.