Thank you for your advice.
When I set "Audio→Custom Sound Effect→File Name" in the dialogue message type script, the message was displayed and the file I set was played at the same time.
Also, for "Set CG", I placed a PNG file with a size of 1920x1080 in "Texture→CG" and was able to display it by using "Meta→Set CG→File name (no extension)".
However, when I place actors in "Actors Setup", the prepared image disappears as soon as it is displayed.
Therefore, it is not possible to use it instead of "Location".