Found it via Aurora store...though downloaded it from your link too. 🫡✌️
Testing TorVPN on GrapheneOS 🤟 
Here is the APK link https://gitlab.torproject.org/tpo/applications/vpn/-/packages/963
Discussion
Use the link. Avoid Aurora and play store. The latter forces play store and google play services to be enabled. problematic if one uses microg.