Ryobi Glue Gun R18GLU 2 glue sticks holder. The good part of it is that it doesn't interfere with using glue gun (with sticks in holder) and allows to hold long sticks (30cm sticks on photo).

Printed from PETG. Mounted using 3x45mm wood screw. Printed tube used to stabilize new long screw.

Fusion 360 source file attached.

Note: R18GLU is model name used in EU. Probably the same thing has different model name in US.