Assalmu alaikum, Please is it permissible to repay prayer that has been left in the past or not? because some people said you cannot pay the past prayers that one left and even if one pays it has been turn to superrogetory instead of obligatory.
Brother obviously you can repay the missed prayers, they are called Kaza/Qaza Prayers or Qaza-e-Umri if you are praying Qaza of all of your missed obligatory prayers in your whole life .
The method of performing Qaza and Qaza-e-Umri are same as Obligatory prayers, just your Niyyah (Intention) is different. When you make niyyah (intention) for Qaza or Qaza-e-umri, you add this line while making intention "I make intention for (Qaza or Qaza-e-Umri) for the 4/2 Rakats of Fajr/Zuhr/Asar/Maghrib or Isha"
If you are praying Qaza-e-Umri for life you should first calculate how many prayers you have missed for how many years and pray one by one. It is advisable that you pray Qaza before or After the respective Fard Prayers, because in this way you will complete Qaza-e-Umri side by side with fard prayer and it will be easier to complete them.
Note: avoid praying Qaza or Qaza-e-Umri in prohibited times for prayers. Like from Fajr to Zuhar and from Asar to Maghrib. Some people say that you can pray Qaza and Qaza-e-Umri in these Hours but I have no valid proof, so avoid these timings.
May Allah (S.W.T), help you in praying all your prayers Fard and Qaza. :)