I don’t know !!
in another thread, LP stated that Polylang is not supported but WMPL is.
I kept Polylang and patched the plugin in order to support multiple courses languages.
It works fine (courses/lessons + checkout process + profile page + emails).
Around 20 files modified + a handfull of actions/filters in child theme function.php
Concerning WMPL, I am a bit doubtful since LP is not built for supporting different courses in different languages but I may be wrong.