Understanding How to Load Local Files in a Teachable Machine

I would like to use local files as learning data in the Audio Project of the Teachable Machine.
You can only upload zip files with audio data previously created/downloaded with Teachable Machine.
It says

I actually recorded it on the Teachable Machine and looked at the contents of the zip file that I downloaded, but it contained the webm file and the json file.
The webm file is a voice file, so there is no problem, but the json file says "FrequencyFrame" at the beginning, followed by real numbers, so I don't know what it means.

Is there any way to create and load the json file?