Included in your SRAM hydraulic brakes is a small T8 Torx tool, meant to install the new barb after shortening the hose.
This is a handle for that tool to snap into.
If IKEA can give you an ergonomic cheap plastic cover for a janky hex wrench, then I can give you this. Park Tool makes a decent tool for the job (DTD-8) but I wish it had larger diameter and coarser knurls.
You might need a punch or similar tool to seat the wrench in the holder. Should snap in place.
Recommend printing this with strong walls and a decent infill % of a suitable pattern. PLA is OK, PETG is better.
The author marked this model as their own original creation.