Yes, there is an API available to retrieve a list of completed modules, learning paths, instructor-led courses, exams, and certifications for a user on Microsoft Learn. The Microsoft Learn Catalog API provides a public web API to retrieve a list of the modules, learning paths, instructor-led courses, exams, and certifications, along with the URLs used to access each <sup>1</sup>. You can use this API to retrieve the completed modules of a user.
To use the Microsoft Learn Catalog API, you can send a web-based query to Microsoft Learn and get back details about the available training content and certification exams such as titles, products covered, levels, links to training, and other metadata and returns a JSON-encoded response with the information <sup>2</sup>. You can use your preferred API requesting method, such as cURL, Postman, etc. There’s no authentication required to access the Microsoft Learn Catalog API <sup>2</sup>.
I hope this helps!