Unable to allow access to my photos for my Nixplay app.

I have a new iphone 13, all updated with iOs 16.5.1 and when I go to add photos to my Nixplay app, the option to allow photos access does not come up when I go into settings. Nixplay worked great on my old phone, iPhone 6s plus but now it says "access was previously denied". I went into the Nixplay settings also and am connected to my Google photos but Nixplay app still won't let me add photos. Keeps telling me to go to settings>Nixplay>Photos and select "All photos", but the photos option isn't even listed. Only options listed when I go to that is: Siri & Search, Notifications, Background App Refresh and Cellular data. And the Background App Refresh and Cellular data are green. Can you help me with this?