I have two questions.
First, is it okay to ask questions about Action Game Tsukuru MV on this site?
If it’s not appropriate, could you recommend a suitable site?
Second, it’s about the camera.
The camera that follows the player is positioned too high, and I’d like to lower it. How can I achieve this?
Sorry I have no help for you, maybe someone knows about Pixel Game Maker can help you
The best place to find PGM info and ask questions is on the Steam forums. アクションゲームツクールMV 総合掲示板 :: Steam コミュニティ Mainly because the English version was called Pixel Game Maker MV. I was confused at first thinking you were talking about Action Game Maker. 
The best way to do this is to make the camera follow another object and that camera object is a child of the player. You can make the child always follow the player or follow with delay and you can adjust the y offset to make it higher or lower showing based on what you need.
I used Google translation.
Thanks. I gave it a try, but the camera speed is really slow. Is there a way to make it smoother? Also, I posted the same thing in the Steam community. Thanks for letting me know.
Do you mean that the follow speed of the camera is slow? Are you doing the child method? Can you show screenshots of the settings you are using?
Awesome! Usually I respond to those, but since we are already discussing here we can continue in this thread.