Problem

The Microsoft Flow Approvals connector does not support sending approval requests to groups today or distributed groups.

To demonstrate the issue I have a sample distributed list (DL) group ‘SomeO365DLGroup’.

The DL group has the following members.

Created a sample manually triggered flow to send and approval with the DL ‘someo365DLGroup@GOV019539.onmicrosoft.com’. I got the following error.

{
  "error": {
    "code": "InvalidApprovalCreateRequestAssignedToNoValidUsers",
    "message": "Required field 'assignedTo' contained no valid users in 
the organization"
  }
}

Step by Step Solution

There is an alternative approach, first to get list of members email from the DL group. We will use the “Office 365 Groups” connector with “List group members” action. The action requires to use the group ID.

Step # 1 : Using Azure AD portal get the group id of the distributed list.

Step # 2 : Create a Manually trigger with a EmailArray variable as Array datatype.

Step # 3 : In the manually triggered Power Automate make a call to the ‘List group members’

The output of the above action is.
[
  {
    "@odata.type": "#microsoft.graph.user",
    "id": "17d7b3e9-7e7c-46e5-b16f-2baef2e6cd46",
    "businessPhones": [
      "+1 732 555 0102"
    ],
    "displayName": "Jordan Miller",
    "givenName": "Jordan",
    "jobTitle": "Auditor",
    "mail": "JordanM@GOV019539.OnMicrosoft.com",
    "officeLocation": "19/3123",
    "surname": "Miller",
    "userPrincipalName": "JordanM@GOV019539.OnMicrosoft.com"
  },
   ... other objects are removed brevity
]

Step # 4 : Loop through the output of the above action to get the mail of the each member. Add the mail address in the EmailArray variable.

Step # 5: Finally use the EmailArray variable to create a string with semicolon delimited string.

Step # 6: Use the output of the above step as the Assigned To field.

Result

The alternate approach to get the list of emails to use in the Assigned to field resolved the issue of the distributed list group mentioned.