Can we get all Azure AD users list using PoweApps?

You cannot get all Azure Ad users using PowerApps, whereas you can list the details of a single user or users within a group.

• Make use of Azure Ad connector that needs administrative permissions for your account like below:

  • Group.ReadWrite.All
  • User.ReadWrite.All
  • Directory.ReadWrite.All

• Connect Azure AD in the app,

  Go to the Data tab -> Add data-> Search Azure AD -> Select Azure Ad connector -> Connect

To get users within a group, make use of below query:

Users= AzureAD.GetGroupMembers("Your_Group_ID").value

To get details of a User, make use of below query:

OnSelect = ClearCollect( colAzureUserDetails, AzureAD.GetUser(txtAzureID.Text) ) 

To know more details, please refer below links:

Power Apps Azure AD Group - SPGuides

Power Apps : Get users from Azure AD to Power Apps view to list table and refresh button for table - Stack Overflow