In order to run Followrio for multiple accounts, you need to run multiple instances of chrome simultaneously. Then install the extension on each chrome, login to desired IG account and set up the extension as you need.
You need to download Google Chrome Portable for multiple chrome instances.
You can download it here:
Run this command in Terminal for each instance changing the ending number accordingly:
mkdir -p ~/MultiChromeData/01
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --user-data-dir=~/MultiChromeData/01