Hammerhead Karoo is able to connect with other third-party service providers & upload activities straight from the device. "Automatic" and "Manual" Activity Upload Modes are applicable only for Strava and Training Peaks for now.
To learn how to connect third-party services, please see: Linking Third-Party Accounts
Here are the steps to change between Automatic and Manual upload modes:
Tap on "Settings" from the Home Screen
Scroll down and tap on "Connected Services"
You will have the option to toggle between "Automatic" and "Manual" Activity Upload modes.