Hi,
You will need some kind of External (web) services plugin developed in Moodle but as Visvanath has mentioned, if you want to do that yourself, you will need to learn Moodle Plugin development.
Apart from the development documentation pages here on moodle.org including the Tutorial at https://docs.moodle.org/dev/Tutorial, and the other resources already mentioned, there is a soon to be launched course (paid) 'Moodle Plugin Development By Example' at https://mukudu.net/publishing/moopluginsbyexample/ that might be of interest or the 'MoodleBites for Developers Level 1' course at https://www.moodlebites.com/mod/page/view.php?id=24546 and a few short specific ones on Udemy https://www.udemy.com/courses/search/?src=ukw&q=moodle+development.
Regards
