Daikin Onecta
Daikin is one of the leading brands of A/C and climate control units. Many Daikin units come with integrated WiFi controls that needs to be enabled. You should refer to your unit paper manual to find out how, usually you need to long-press some buttons after opening up the front cover and reading the WiFi hot-spot information written there.
Now, up to 2020 it seems that most of those unit come with a smart interface that can be controlled locally, but unfortunately since at least 2023 they now come with a so called Onecta smart module. This module cannot be controlled locally, but luckly there is an extension for Home Assistant for this use case too.
Home Assistant
Home Assistant has a native integration with the older, local Daikin smart modules. Unfortunately, in my case, i have the new Onecta units.
Luckly, in the HACS extension, there is one integration called Daikin Onecta that relies on your Onecta cloud account.
So after you have registered your Daikin devices with Onecta, created an account and added them to your Onecta app, you can configure this extension to link to your Onecta accound. Your Daikin devices will appear in Home Assistant and you will be able to fully control them.
At this point you can also uninstall the Onecta app form your phone.