I want to ask a question

I applied in my department for departmental permission certificate to apply for a post in ppsc. I send my filled ppsc form of departmental permission certificate to secretary of my department.

Now secretary of my department has forward a letter to ppsc saying that kindly find enclosed herewith departmental permission certificate duly signed in favor of me.
I have also received a copy of this letter.

Now the issue is that how i am certain that ppsc has received my proforma.

What i would present at the time of interview.

I fear that if i only present forwarding letter they will reject me saying that you have to present that particular form of ppsc departmental permission certificate.

Kindly guide me. Iam anxious about it.