I finished the instructions to the backpack!
I hope you enjoy making this project! I have added a quick overview as well if you just want a peak at the project.
DETAILED INSTRUCTIONS PART 2:
QUICK OVERVIEW:
Free Pattern:
Please note: This pattern has been updated. There was an error on the original pattern. The bottom pocket gusset should measure 12.75 inches in length. Sorry for the inconvenience!
learncreatesew 
Thank you so much for this pattern. Can you please share a link to the hardware (rectangle rings & triglide slides). I’m having trouble finding them.
Thanks for letting me know! I tried to add links but for some reason they aren’t working properly. I will try again tomorrow and see if I can get them to work!
Until then, both items can be found on Amazon. I have listed the item descriptions, so it should come up if you enter the key words in the search bar and search in Arts, Crafts, & Sewing. Sorry for the inconvenience!
Rectangle Rings: Many of these had very delayed shipping. A combo sized pack was the only plastic set that I could find that had reasonable shipping. You can also often find metal rectangle rings. I usually purchase rings with interior dimensions 1 x 0.5 inches. Here is the description of the item I found.
Gourd Rectangle Plastic Dee Ring D Webbing Belt Ribbon Buckle 40 Pcs Included 3/4″, 1″, 1-1/2″, 2″ Each 10 Pcs
Triglides:
BEADNOVA Slide Buckle 1 Inch Triglide Slides Plastic Webbing Slider for Strap Belt Backpack Handbag DIY (30 Piece, Black)