The app Heart Rate On Stream sends your heart rate from your Wear OS watch to your phone and finally to OBS Studio on your PC using the free open-source plugin obs-websocket.
For example you can include your heart rate in your Twitch live stream or video recordings. The app works without an internet connection as the heart rate is transmitted to your PC via your home network.
The phone app provides a home screen widget for quick connections and
the watch app provides a complication and tile for displaying your heart rate and opening the app.

This app requires:
• OBS Studio version 25 or above --> https://obsproject.com
• obs-websocket plugin version 4.8 or above --> https://github.com/obsproject/obs-websocket/releases

Streamlabs OBS is not supported.

Supported Watches... (last updated 21 Oct 2022)
Casio: GSW-H1000 | Smart Outdoor Watch WSD-F1 | WSD-F20 | WSD-F21HR | WSD-F30
Fossil: Gen 5 LTE | Gen 5e | Gen 6 | Fossil Q | Sport | Wear | Wear OS by Google
Guess Wear
Google: Pixel Watch
Huawei: Watch 2
Hublot Big Bang e
LG: Watch Sport | Watch Style | Watch W7
Louis Vuitton Tambour Horizon
Mobvoi TicWatch: C2 | E2/S2 | E3 | S/E | Pro | Pro 3 Cellular/LTE | Pro 3 GPS | Pro 4G | S
Montblanc: SUMMIT | Summit 2+ | Summit Lite | Summit 3
Motorola: Moto 360
Movado: Boss Touch | Connect | Connect 2.0
Nixon The Mission
Oppo: OPPO Watch
Polar: M600
Samsung Galaxy: Watch4 | Watch4 Classic | Watch5 | Watch5 Pro
Suunto: Suunto 7
TAG Heuer Connected: Calibre E4 | 2020 | Modular 41 | Modular 45

Why not mine?
Your watch does not support real-time measurement or does not run Wear OS.