You will need to introduce an intermediate step. See the examples here (where I say “Example 2 – With the interim popup panel”).
Basically, if you are starting the lightbox directly for the album, you will be restricted to 100 photos. But if you show the “interim popup panel”, first you will see a screen (something like a popup) with the photos in the album, and you can click on the individual photos to start the lightbox. In this popup you can add a “More” button, which will let you click on the button to see more photos.
If you are using the shortcode or block builder (i.e. the “Add / Edit Photonic Gallery” button), after you have selected the layout you want to use, you will see an option, Show an overlaid popup panel. Set that to “Yes”, and it will activate two fields – Number of photos to show in overlaid popup (set this to 100) and “More” button text in overlaid popup (set this to “More”, or any text that you prefer). Alternatively, you can directly add these attributes to the shortcode: popup="show" photo_count="100" photo_more="More"
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