Search by tags instead search by names

Hi! First of all, great work! This plugin is really well designed and I love it. 🙂
For my master degree I’m doing a website with WordPress, using PhotoGallery to manage hundreds of photos divided in albums by theme (the website is to show the work of an italian photographer). I really need a way to make it possible to search images by tags. For now, the plugin only do a search by name, but I’ve found the query to search by tag in the code and It seems to be inactive. I really need this function for my site, or I have to change my entire work.
I hope you can help me.
Thanks a lot!

https://wordpress.org/plugins/photo-gallery/