Recommended to print with filament change after the base section (up to layer 10 if print with 0.2mm layer height) to vary the text and HUDs colors.
Print the HP and mana bar separately and fit/glue into the space below the names. Can customize the length to alter their lengths.
I use the Carabiner printed from here: https://www.printables.com/model/401769-oval-carabiner-7-sizes to hang onto the collar.
For customizing text as the screenshot below, you can use Prusa slicer 2.6 (https://github.com/prusa3d/PrusaSlicer/releases/tag/version_2.6.0-alpha6) with the empty version of dog tag stl.
The author marked this model as their own original creation.