It's not exactly that but i'll try to explain compatibilities and incompatibilities.
The overall Video DownloadHelper product is made of 2 parts, the browser extension and the coapp. In very simple cases (the web site provides an URL to download the complete video), the coapp is not necessary but given the evolution of web streaming technologies, this now happens rather seldomly.
The companion app is both OS and processor dependent. The only supported processors are Intel/AMD, 32 and 64 bits. There is a special case of Apple ARM M1 processor that is supported because Apple provides some kind of processor bridge called Rosetta.
On Windows, the installer file contains both 32 and 64 versions and is smart enough to automatically pick the correct one at install time.
On Mac, there is only Intel/AMD 64 bits and ARM M1 (through Rosetta). The coapp installer exists in 2 versions, PKG (the preferred way) and DMG (which requires an additional step to setup the manifest files at the correct locations).
On Linux, both Intel/AMD 32 and 64 bits versions exist and you have to pick the correct one. The install packages might be in .deb (for Ubuntu and Debian) and .tar.gz (all distributions). One tricky thing may be the GLIBC (the main general purpose OS library) version: if you try to execute a version of the coapp that has been compiled with a certain version of the GLIBC, on a old Linux distro that has a former GLIB version, it won't work. This is why, for those users, we provide builds of the coapp for GLIBC 2.23 and 2.27. Assuming you are running an up-to-date Linux, the default coapp runs with GLIBC 2.31.
There is currently an issue with latest distributions of Ubuntu. The latest distro version, 22.04, installs Firefox using a new method called snap. It makes the browser run in an isolated sandboxed environment. This might be good for security but then, the browser cannot access the coapp (which is installed out of this sandbox). Mozilla is aware of this issue and should be working on a fix. For now, the workaround consists of installing Firefox manually from a package downloaded from https://ftp.mozilla.org/pub/firefox/releases/
Hope this helped understanding what works with what.