Open My data in the Welltory app
Select the required category, for example, Activity
Scroll down or tap Sources
Tap icon of the app you need. If the source requires integration with Apple Health, Connect via Apple Health will be indicated
If Apple Health isn't connected yet, you will be prompted to connect it.
Tap Turn All Categories On
Go to source app's Settings and enable data transfer to Apple Health
Some sources can be connected to the app directly, like Fitbit, Withings, Garmin, etc.
A direct integration gives additional charts to track your workout heart rate, steps, cadence & heart rate zones, activity breaks, cardio volume, strength intensity, and more.