Within the Spire Health Tag app, go to Settings->Your Health Data. There should be a green switch to the right of "Share with Apple Health".
To ensure that the Spire Health tags are writing data to the iOS 13 Health App, we'll want to take a look at your iOS settings to make sure they are set up correctly. From your phone, go to the Settings icon, then go to Privacy-> Health. Within the Health section, you should see a Spire app icon listed under Apps. Tap on the Spire icon and on the next screen make sure that "Turn All Categories On" at the top of the screen is listed as "On" vs "Off". Heart Rate, Respiratory Rate, and Steps should all have green switches to the right which would indicate that these data types are writing information to the iOS health app.