@Progon
Trojans supposedly were mentioned by Egyptians as part of the sea peoples.
From Ramses III tablet:
https://en.wikipedia.org/wiki/Sea_Peoples
This one is a bit controversial. There is no consensus if the tablet is genuine, but given the time it apeared and the reputation (accused of forgeries, not really substantiated
https://en.wikipedia.org/wiki/James_Mellaart#Forgeries) of Mellaart who excavated Çatalhöyük site in 1961 I would not be surprised either way. Hittite was not desciphered at the time the tablet was discovered, so my guess is it would have been impossible to forge. See the below link:
https://www.livescience.com/60629-ancient-inscription-trojan-prince-sea-people.html
"
Zangger and Woudhuizen said that it would be extremely difficult, if not impossible, for Mellaart or someone else to create such a forgery. The inscription is very lengthy, and Mellaart couldn't read, much less write Luwian, they said in their paper. They also noted that nobody had deciphered Luwian until the 1950s, which means that Perrot wouldn't have been able to forge it either. Zangger and Woudhuizen added that few scholars today are able to read Luwian, much less write a lengthy inscription. They said they also don't understand why Mellaart would have wanted to create a lengthy and complex forgery, but leave it largely unpublished. [24 Amazing Archaeological Discoveries]"
According to Eric H. Cline, 1177 B.C.: The Year Civilization Collapsed ISBN: 9780691140896S (I just listened to the lectures have not read the book yet) but it seems there is not enough information regarding the Sea Peoples or Troy for that matter to make any conclusions, if the invasion happened before or after the fall of Troy, or whether Troyans participated.
My personal opinion, it happened after the fall of Troy. And the armies of the Sea Peoples were the same armies participating in the siege of Troy, who decided to take a stroll across the region sacking the Hittites, Levant, and Egypt. Would be in line with Odyseus taking 10 years to return home xD.
Bottom line is no one knows.