You don't need to convert it, just find the song that you want and the credit should automatically be used to 'pay' for it : How iTunes étoffe purchases are billed : This situation contains user submitted content, comments and opinions and is cognition informational purposes only. Apple may provide https://caidenbqdqc.wikikali.com/1045887/le_meilleur_côté_de_prepaid_itunes_credits_aanbieden