Traditionally, sports- and smartwatches have not been able to send heart rate data to apps like Motosumo. Recently, this has changed, and some watches have started opening up for this functionality, allowing you to use them to track your heart rate with Motosumo. The procedure is different from watch to watch, so you can always try to check with the watch manual or google for specific instructions.
A few popular watches that started opening up for connections to other apps are from Garmin and Samsung. You can find instructions for the specific watches below.
Garmin
You can see a list of the watches from Garmin that can connect on this link:
https://support.garmin.com/en-US/?faq=Zj1947s6pqAHzBCAhLhrC9.
On this link are the specific instructions for the Vívoactive, one of their most popular watches.
Samsung
You can find a guide for Samsung watches on this link:
https://www.reddit.com/r/GalaxyWatch/comments/py3y4j/broadcast_your_galaxy_watch_heart_rate_to/
Other brands
Other brands have started opening up for this functionality, so you can always try to google instructions. If you have a question about your watch or anything else, don't hesitate to get in touch with us at support@motosumo.com.