I was able to find this. Haven't attempted it yet but it appears that it is in fact standard TOTP, only the VIP app generates the seed and you have to provide the seed to (in this case) Fidelity. https://gist.github.com/jarbro/ca7c9d3eebba1396d53b4a7228575...

And yeah, my biggest problem with it is that I already have a solution for TOTP; I don't really want to also figure out some solution for their proprietary garbage.