I'm trying to create a similar effect to this. And I found a nice tutorial with something similar. However, I wasn't able to add a text there. So it looks like the material setup is not using any volumetrics at all? Can you help to decipher this shader?
I get something pretty close:
I've created this mesh from the logo:
Then I've given it a pure white Emission shader for the bottom, and this node setup for the walls, which is basically a mix between an Emission of a multicolor ColorRamp and a Transparent, with a gradient along the Z axis, and before the Output, a Layer Weight to give it a pink emission on the edges:
If you want to animate, use an empty in the Texure Coordinate to mix the materials with a Transparent node: