Example use of Netatmo API shortcut, which is required for use:
https://routinehub.co/shortcut/5395

Gets the CO₂ data from your indoor weather station for the last 12 hours and displays a notification with peak and current levels.

Can be called from another shortcut with "silent" to return text for use in Automations

Requires the indoor weather station device ID This can be found on the Netatmo Weather app under Settings > My Stations > Station > Indoor Module > MAC Address