Apple Home requires set-up code

I bought the led bulb and installed it in my room few years ago. And I changed my phone recently. I wanted to add the light to Apple Home App through Yeelight app, but it requires set-up code. (I followed instruction on this page: Yeelight) I don’t have the box, and I cannot check the qr code on the bulb - it is installed in closed lampshade. How can I add the bulb to Apple Home?

(Or, I would like to set ‘location’ as trigger to activate automation. I want to turn on light when I get back home, and turn off when I leave home. But I cannot find how to set a trigger.)

If you just changed your phone but not your Apple account, you only need to log in to your original account and all the lamps in the previous app will be displayed.
If you want to add it to Applehomeapp, you must get the code from the lamp body before you can add it.