How can I run a gallery in theme Photographer v1.4.0

I have problems to make the gallery run in the theme Photographer v1.4.0.

This is, what I have done:
1 step: I installed mamp 3.5.1
2 step: Then I installed grav + admin as localhost.
3 step: I installed the theme “photographer” v1.4.0.
4 step: setup a page with page-template "gallery"
5. Uploading some fotos
… But what do I have to do, that the gallery-page runs this fotos?

Thanks for tipps!

This theme and the skeleton does not come with a blueprint, so in expert mode, add in frontmatter:

        filter: 'yourfilter'
        image: yourimage.jpg
        description: 'your description goes here'
        filter: 'yourfilter'
        image: yourimage2.jpg
        description: 'your second description goes here'

And so on, for each image.

Thanks for the tipp! I got it now and the gallery shows some pictures.