User documentation is in “Intervalo harmônico”.
Here is a minimal lesson file:
header {
module = harmonicinterval
lesson_id = "a400df62-e007-4a1b-9057-cd05397e88a2"
version = "3.1.4"
title = "Seconds"
intervals = [1, 2]
test = "3x"
test_requirement = "90%"
}
Additional variables you can put in the header. Click on the link to get an explanation: