MS Flow Approval Mail

Hi All,

Can someone help with how we can send approval email to addresses with other domains for eg- contoso.com and not contoso.microsoft.com

If I am using onmicrosoft.com, my flow works fine but other than that it throws below error-

BadRequest. The request failed. Error code: 'InvalidApprovalCreateRequestAssignedToNoValidUsers'. Error Message: 'Required field 'assignedTo' contained no valid users in the organization'.

Any help would be appreciated.

Thank You.