Is there any way to load all photos into a lightbox please?
You can’t. The lightbox will only show what is already fetched. The only way to get 100+ photos in the lightbox is to first load all photos of an album on the page (i.e. use the “Photos in an album” feature rather than “All albums”); you cannot get the lightbox to show 100+ by clicking on an album thumbnail.
Or is it possible have a link directly to Google Photos Album website instead of lightbox?
No – Google Photos Albums cannot be linked directly due to various constraints in the API. But, you can try Example 3 here. That will let you display all photos of your album on a separate page. You can use the more and photo_more feature as documented to show a button on the new page, and your lightbox will pick up any photos added via those buttons.
