We ahmadi muslims don’t need any certification from anyone. A rose is a rose is a rose. We follow prophet muhammad(pbuh) and accepted hazrat mirza ghulam ahmed (as) as per the his(pbuh) prophecies. HMGAQ (as) is not a replacement (na auzubillah) of the holy prophet (pbuh). He(as) is a follower and ummati of the holy prophet (pbuh). BTW, according to your belief, Jesus(as) will become the last prophet.