How to loop on only 1 request in folder all iterationdata

Hello,
I have search many time, but i don’t find the good result.

I will try to explain what i try to do.
i have a datafile with many itération (1000).
i have a collection with many folder.
I go in Postman runner, and choose my folder.
This folder has 4 request:

  • Authentification -> i would like to execute this one only if i don’t have the cookies, but it’s not important
  • List Activity -> This one create a variable environnement which is needed by the next request
  • Create Groupe -> this one create a groupe for each iteration
  • Disconnection

I would like to run runner, and execute only 1 time:

  • Authentification
  • List Activity

And 1000 times (or more that dépend the count in my datafile):

  • Create Groupe

And finish with only 1 time:

  • Disconnection

Can you Help me?

no idea? :’(
i search everywhere and try a lot of things… but KO