I need to create Azure AD users in bulk (about 90), in order to add each of them:

* To a SharePoint group present in 90 sub-sites
* Authorizations from two libraries in each of these sub-sites

Example :

* User: "user1@mydomain.com"
* SharePoint sub-site: "<https://mydomain.sharepoint.com/sites/principalsite/sub-site1>"
(already created)
* Two document libraries: "Library1" and "Library2" (already created) for which the user "user1@mydomain.com" must be added to the
authorizations of these two libraries, with a specific authorization
level "Special authorization" (already created)

---
* User: "user2@mydomain.com"
* SharePoint sub-site: "<https://mydomain.sharepoint.com/sites/principalsite/sub-site2>" (already created)
* Two document libraries: "Library1" and "Library2" (already created)
for which the user "user2@mydomain.com" must be added to the authorizations of these two libraries, with a specific authorization level "Special authorization" (already created)

Etc Etc Etc..... Up to 90.

The idea would be to create a PowerShel script based on a CSV file with the necessary information:
UPN > Sharepoint link > Sharepoint group name > Document library names > Name of the specific authorization level.

I don't really master scripting and I don't know much about the powershell functions related to Sharepoint.
After some research, I find information but it doesn't really correspond to my needs.

Can you help me ?

Regards,