Download Modulr Hub.
The desktop app that signs you in, holds the licences linked to your account, and installs, updates and removes the suite. It is never required: a plug-in plays with the Hub closed.
Opening it the first time
The Hub is signed with a Developer ID and notarised by Apple, so macOS opens it normally. Unzip it, drag Modulr Hub into Applications and open it. The first time, macOS says it was downloaded from the internet and asks you to confirm: press Open.
Check the download first, if you like: shasum -a 256 on the zip should print the SHA-256 above. On Windows, unzip the download and open Modulr Hub from the ModulrHub folder inside.
Logging in
Open the Hub and press Log in at modulr-audio.com. Your browser opens at the site with a code; log in there and link the Hub. The site gives it a personal access token linked to your licences, and the licence for each product you bought is written where the plug-ins read it. Logging out revokes the token and leaves the licences in place.
Other platforms
The Windows build is on the card above. Linux builds are not published yet: the Hub is written for it, and one will appear here when it has been built and tried.