In the past days I have been trying to figure out how to send data to thingspeak, but I must have been doing something wrong, because no data is visible on my feed...

So what I am trying to do: send analog values to my thingspeak chanel. I have set up a fresh install of the latest esp easy normal core on a wemos d1. Here I have a soil moisture sensor connected to the analog port. Data is visible on the ESP: I would like to display the data on my TS channel.
For this I have added the ThingSpeak controller with the following: Next I have configured the device and enabled the Data Acquisition: Finally checked the cart on the TS. No data is visible...
Checking the log on the esp, I can see that there is a connection error: I have checked the esp's configuration. It seems it is correctly connected to my network: Also checked the ThingSpeak channel:
The write key seems to be right (just copy-pasted).
What I am unsure is the ThingHTTP name: field. What shall I write here? Now that is set to my channel ID, but also tried with my username.
Or have I miss-configured anything else?
Thank you for your help!
Cheers
Paul