To add a custom list open your developer console and run setCustomCourseList
with the JSON string you want to use.
For example:
setCustomCourseList('[{"name":"test", "id": 1}]')
To set a custom link to fetch run setCustomCourseLink
with a string of the link you want to fetch.
Make sure the CORS policy works.
For example:
setCustomCourseLink("https://www.example.com")