I used Develop on My MacBook Air laptop to get the sign on INSTAGRAM, but the sign goes to a dud Photo Library that won't open. I have the Photo Icon on my screen and it opens to All my photos. How do I make the sign access all my photos?

I used Develop on my MacBook Air laptop to get the + sign on Instagram, but the + sign goes to a dud Photo Library menu that won't open. I have a Photo Icon on my screen that opens and shows ALL my photos. How do I get the + sign on Instagram to go to an active Photo or Photo Library Menu that will open and show ALL my photos? I need to upload photos to Instagram on my MacBook Air laptop.