Hi Mohammed,
i. Has this worked before? Please go to the Close activity notification details and double check that the it is enabled to send the survey.
ii. Does other notifications work?
iii. I see you are also working with a ServiceDesk version (r12.5) that is no longer supported for several years now. You should consider upgrading to supported versions r14.1 or r17.0 in case you need log a case for assistance from Support.
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Kind Regards,
Brian