By Default the requires roles are not install. to install them simply folly the instructions below
.Login to the server.
•Launch Exchange Management shell.
•Type Add-pssnapin microsoft* and hit enter.
•Type Install-CannedRbacRoles and hit enter.
•Type Install-CannedRbacRoleAssignments and hit enter.
•Type Get-ManagementRole “reset password”
you should then see output similar to this
Reset Password ResetPassword
the next step is to add the new role to a security group. in this example we will use "Help Desk"
New-ManagementRoleAssignment -SecurityGroup “Help Desk” -Role “Reset Password”
open the EAC in your browser. For example https://mail.domain.com/ecp
Click on permission, Select Helpdesk, then add a user to the security group. select a user and click edit.
log out of ecp and back in and you should now see the reset password option