Here is what is said:
THE OPEN LABS “STAGELIGHT MONTHLY MUSIC CONTEST II” IS A NO PURCHASE NECESSARY CONTEST.
The contest is open to individual, aspiring music artists who are 13 years and older. Your submission must be of an ORIGINAL SONG and you can submit more than one song per month. To submit, simply follow the upload instructions on the contest page and upload either an mp3 or .wav file of your song. Your original song can be with or without lyrics, but must be specific to the month’s genre (i.e. Rock, EDM, Hip Hop or Wild Card). If you haven’t already recorded your song, we recommend you use Stagelight – The Easy Way to Create Music. You can download the app for FREE here ($9.99/USD value).
I would recommend to go the homepage and peep the prices and listen to what people are submitting etc...
So it is not necessary to use Stagelight but can get a paid version for free if signing up for submitting content.
Homepage with rules and prices etc: