This tool generates default SDP Offer/Answer messages from the web browser you use to run it, and uses that to generate an equivalent mediasoup RtpCapabilities object.
Run it like this:
cd mediasoup-sdp-bridge/
npm install
npm run build
cd tools/browser-rtpcapabilities/
npm install
npm run startNow, open a web browser at http://127.0.0.1:8080, and click on Run.
The topmost output is source code for a JavaScript object, which you can copy-paste into the file mediasoup-sdp-bridge/src/BrowserRtpCapabilities.ts.