Make sure you are part of the Organization Management group.
Application Impersonation Role is an inbuilt role, most of the organization may have already had setup this role Group for application access and Reporting.
To check if the group information and member of the group can use the below CMDs
See all role groups
POWERSHELL
Get-RoleGroup | ft Identity
You can check membership using below CMD
POWERSHELL
Get-RoleGroupMember -Identity ApplicationImpersonation| ft Identity
If the Role Group not found then you can set the up the same using the below CMD.
POWERSHELL
New-ManagementRoleAssignment –Name:Appimpersonation –Role:ApplicationImpersonation –User:Admin@Lab365.in
To add a member to role group use the below CMD.
POWERSHELL
Add-RoleGroupMember -Identity Impersonate -Member Admin@Lab365.in
http://msdn.microsoft.com/en-us/library/office/bb204095(v=exchg.140).aspx.aspx)