Upload quantized mesh tile to ion

Hello,

assuming one has managed to create his own quantized-mesh tiles,
is it possible to upload those directly to ion as you can do for example
with tif?
I mean, I've tried to simply upload a produced .terrain file but it doesn't work. Which does sound reasonable if i understand everything correctly about how the tiling system works, but is there a way to upload your own quantized mesh to ion?
Is it only possible with a .terraindb and if so, how can one create such?

Thank you in advance.