Welcome to the forum.
Did you check the user manual? I had a quick look but couldn't find a specific function, apart from it saying that a new file is created when it reaches 2GB in size. This is probably a limit due to the underlying file system on the card, so it wouldn't be adjustable as such....
However, the file format/quality defines how much space a recording needs, so if you're ok using a lower quality, the recording will take longer to reach 2GB and you should get a longer recording time per file. There's a table in the manual where you can check this.
