Open blender and then open the blend file from your downloaded folder.
Or import the vdb's
You can import the vdb's through the volume menu. Mark all files at the vdb folder with A and import them:
The 440 frames long bonfire animation can be scaled up and down or can be changed in the density and color with the principled volume shader.
$15
The 480 frames-long bonfire vdb sequence has faster flames and a longer frame length.
It can be scaled up and down or can be changed in the color with the prepared principled volume shader.
$15
The 121 frames-long vdb sequence is looped and can be animated in Blender endlessly using the tips in the video below.