Please see the error on your page:
Google has deprecated the Picasa API. Please consider switching over to Google Photos
As this error states, you are trying to use Picasa, which Google killed 3 months back. How are you able to use Picasa with Photonic? I have taken out all capabilities to use it from the plugin.
Please note this point from the support topic I have linked above:
Then, rebuild each of your galleries one by one using Google Photos. Hopefully the “Add / Edit Photonic Gallery” button that you see in your editor (if you are using Gutenberg this is the Photonic block) will help you with this.
If you have set up your Google Photos authentication, you will have to delete the existing Picasa Gallery and re-create a Google Photos gallery for the same album. Google doesn’t have a mapping between old Picasa and new Google Photos galleries, so this is a manual process. As written in the documentation, use the “Add / Edit Photonic Gallery” button.