I am no longer willing to maintain the packages to the latest version as I no longer use them.
You can use this as the template of your repo and maintain if you want.
These packages are not official, they are neither supported nor endorsed by the official Solus devs. Do not ask for help in Solus's help forum, instead create an issue here.
Now you can directly download the compiled .eopkg files from here
To install any program directly from eopkg file, First download the file and then cd into that folder like $ cd ~/Downloads, After that run
$ sudo eopkg it ./your-program-name.eopkg
NOTE : Please read the release notes first to know if their are any extra dependencies or not
For Microsoft Edge Dev:
$ sudo eopkg bi --ignore-safety https://raw.githubusercontent.com/prateekmedia/Solus-3rdParty/main/browser/microsoft-edge-dev/pspec.xml && sudo eopkg it microsoft-edge-dev*.eopkg && sudo rm microsoft-edge-dev*.eopkg
For Figma Linux:
$ sudo eopkg bi --ignore-safety https://raw.githubusercontent.com/prateekmedia/Solus-3rdParty/main/graphics/figma-linux/pspec.xml && sudo eopkg it figma-linux*.eopkg && sudo rm figma-linux*.eopkg
For Magnus:
$ sudo eopkg bi --ignore-safety https://raw.githubusercontent.com/prateekmedia/Solus-3rdParty/main/graphics/magnus/pspec.xml && sudo eopkg it magnus*.eopkg && sudo rm magnus*.eopkg