Xiaomi
Set Up Device Pairing for Messages on Web auf Xiaomi
Messages for Web lets you send and receive texts from a browser window on your PC or laptop instead of typing on your phone screen. The connection relies on a QR code that links your phone's Messages app to that specific browser session.
If the pairing was never set up, or the browser storage got cleared, the web page only shows a QR code and nothing else works. Signing out of the browser, using a different browser, or switching to private/incognito mode also breaks the link, since the pairing is tied to that browser profile.
To pair your phone, open Messages and go to Menu. Tap Device pairing, then select QR code scanner and follow the on-screen instructions to scan the code shown on the Messages for Web page in your browser.
Once paired, your phone needs an active internet connection to keep the browser session working, since messages still route through the phone rather than directly through the web. If you regularly switch computers, you will need to repeat this pairing on each new browser or device, since one QR scan only links one browser session at a time.