I believe alien space crafts are real because I have seen them and been inside of them.
I have my own proof, and my family has experiences with me, as well as some of my friends, old and new.
It is the rule that alien experiencers are not personally given any physical evidence by the aliens.
This is to protect the experiencers and allow them to continue their work with the aliens and in the UFO field.
Almost all alien "evidence" that people claim to have personally is false.