This is not necessary: “install.sh” is executed automatically when running “volumio plugin install”.
IIRC it is not recommended to use “sudo” when running “volumio plugin install”.
After connecting to Volumio via SSH I would do something like the following to download the .zip file ashthespy has uploaded and install the plugin manually:
curl -L https://community.volumio.com/uploads/short-url/xWzEWvQ0cYeH8YwGhctGfSLpYs3.zip -o ir_controller.zip
mkdir ir_controller_3.4.7
miniunzip ir_controller.zip -d ir_controller_3.4.7
cd ir_controller_3.4.7
volumio plugin install
After the installation has finished press Ctrl-c.