Here is a tutorial that shows how to turn a separating zipper into a closed end zipper.
Separating Vs Closed Bottom Zippers
How To Sew A Separating Zipper: Top-Stitching And Faced Method
DIY separating zipper, any length.
How to Use Zippers by the Yard - MHS Blog
How To Sew A Separating Zipper: Top-Stitching And Faced Method
Turn a separating zipper into a closed end zipper tutorial
No Fear Zippers — all well
Zipper Tutorial by my mom :) — Tanis Fiber Arts
Change a Double Zipper to Close in the Centre {tutorial}
No Fear Zippers — all well
Zipper Guide – Pattern Adventure
How To Shorten A Metal And Plastic Separating Zipper At Home
Zip Tips: How to shorten and install a separating zipper - Hey
Zipper Guide – Pattern Adventure