how to add media to "media gallery"?

I’m trying to create a dashboard for uploading info into a dataset.
In the dataset there is a “media gallery” field (which can contain several images and videos).
Unfortunately I can’t find the correct way to upload and submit a number of images at once,
I tried the “upload button” but that’s not working, and I don’t see how can I use the code to do it.

The dashboard is for users to upload images into a dataset, so they suppose to be able to do it for multiple items at once.

I don’t won’t to use a number of fields - one for each image, so can anyone help?

There currently isn’t a way to upload multiple files at once, but it’s in development ! Keep an eye out for it releasing soon.

Is there a way to upload files one-by-one to the media gallery field?