Help to understand heating configuration

Good evening.

I am a total beginner and I am confused.

I am trying to set up a smart heating configuration. What I don´t understand is wether I should configurate the thermostat via the fritz box or via home assistant.

In the fritz box I already have the option to set temperatures for the whole week and I don´t know how to disable the whole function. (there would be two devices sending commands otherwise or is home assistant overwriting the router?)
Of course I want to be able to use all the functions in home assistant and not only just see the diagrams of the temperatures. Do I need another Intergration or Add-on to be installed in home assistant or how do you use your thermostats?

My configuration is the following: raspberry with home assistant, Fritz box as router and my smart heating thermostat is a Fritz Dect 301. I had no problems with discovering the devices.

Thank you for you help!

Hi Konstantin,
I am stuck now with the same issue & questions as you around one year ago.
Do you have a solution to this by now?

Thanks in advance

Hallo, in der Fritzbox habe ich nur die eco und Komforttemperatur festgelegt und die Fenster auf Funktion. Timer usw. wird von HA geregelt und an die Fritzbox gesendet die dann den Thermostaten steuert.

Thanks for the Quick reply.
1)I tried to set Eco and comfort mode in home assistant via developer tools, but immediately after setting it to a new value, it got reset to the ‘default’ values set in fritz! Smarthome. Is there any chance of adjusting these values in HA?
2) the thermostats fritz!dect 301 are listed as ‘automatic’ in fritzbox. Is there a possibility to put them in manual mode and set every parameter in home assistant?
3) if setting a schedule in home assistant (eg via the scheduler lntegration) - will these schedules be in fritz! Smarthome and also on the thermostat display themselves?