Question about Schwinn 800IC

This is no problem if your Garmin watch can send the heart rate, as is the case with the Fenix, for example. Select the option Send heart rate under the settings Sensors and accessories/Heart rate. To establish the connection with the IC8, you may also need to press and hold the Bluetooth button on the IC8. It is also possible to send the heart rate directly to other devices such as Zwift.

I would also be interested. Haven't managed to take pulse directly yet

I can't answer that because I don't have a garmin sports watch.