User documentation is in la section intitulée « Chanter l'intervalle ».
Here is a minimal lesson file:
header { module = singinterval lesson_id = "a400df62-e007-4a1b-9057-cd05397e88a2" version = "3.1.4" title = "Thirds" ask_for_intervals_0 = [3, 4] test = "3x" test_requirement = "90%" }