"Embedding Form (import@)" example not saving data in page header

@giulio.scattolin, I presume you are using the example in a page blueprint?

When creating a blueprint for a page, fields that need to be saved into the header of the page need to be prefixed with header.

So, in your page blueprint, the snippet for the included form should then look like:

form:
  fields:
    header.gallery.images:  <-- Added prefix 'header.'
      type: list
      label: Images
      fields:
        .src:
          type: text
          label: Image

After adding items 'image1' and 'image2' to the list, the following values will be added to the page header:

gallery:
  images:
    -
      src: image1
    -
      src: image2

Hope this helps...