Well there is not any direct method but you can this api call that we are using to build the graphs :
http://your-site.com/wp-json/wplms/v1/user/chart/course
This hit will include a Authorization : token_value in headers .
refer :
http://prntscr.com/kicff8
its return will be :
{
"labels": [
"Course 1"
],
"data": [
100
]
}
The token sent in headers is user specific .user id identified by this token ,
to get token refer api docs :
https://vibethemes.github.io/wplms-docs/developer-guide.html#main-enpoints