The following way worked for me:
- Via Yeelight app on my [Android] phone, I added the lamp. [probably, you can skip this step and connect your lamp directly in the Mi Home app, but this didn’t work for me. And I have no clue why]
- The lamp has appeared in the Mi Home app.
- In the settings of the app (three dots on the upper-right corner) → Additional settings → Network info, I found the IP (I knew it) and token (that is what I was looking for).
- In the HA app → Settings → Devices & Services → Add integration → Miio for Yeelink → Enter a lamp IP and Token.
- Profit.
All in all, all this fun with Xiaomi-ish stuff, slowly but surely, is redirecting me towards more expensive but predictable smart home systems…
