If you want to change an existing passcode for the smart lock, you can follow these steps:

1. Tap your Smart Lock R20 on the devices page in the Eufy app.

2. Go to "Share Devices" under the Avatar section at the bottom right corner of the screen.

3. Find the person you want to change the passcode for and input a new code.

If you have any questions, please contact us for further assistance.