Unfortunately, we might be of a little help as this is beyond our scope of support. However, as you're facing issue linking your Google Photos to Roku via Photo View app, I's suggest contacting the Roku support team for further assistance.
Hi
Melinda Ritter, you can view your Google photos by using the photo view
channel. If it is not working, you need to remove this channel and add it again
after some time. You can also use screen mirroring option to view your photos
on Roku player. If your issues not solve, contact Roku free support team.