Telsa T-Smart Immersion Heater add-on

Having an issue adding the above in repository:
GitHub - britkat1980/tsmart

Any help? thanks.

Cmd(‘git’) failed due to: exit code(128) cmdline: git clone -v --recursive --depth=1 --shallow-submodules – GitHub - britkat1980/tsmart /data/addons/git/7a479cc9 stderr: ‘Cloning into ‘/data/addons/git/7a479cc9’… fatal: protocol ’ https’ is not supported ’