How write decimal values in channel fields using MQTT client | General | Forum

Hello everybody,
I am getting lost trying to update numbers with decimals to a Channel using a MQTT client.
I am trying to follow the directios found here https://it.mathworks.com/help/thingspeak/use-desktop-mqtt-client-to-publish-to-a-channel.html

sending a string like
field1=4.1&field2=10.11&field3=11.5
but values are not loaded (I read thet null values are pushed in the fields
created_at":"2020-12-15T17:28:27Z","entry_id":3,"field1":null,"field2":null,"field3":null
)
How loading of single/gloat values can be accomplished?
Should I multiply the values and truncate them and then reprocess them in thingspeak?

I apologize, but I am a new user and I am still struggling to get things
Your help relly appreciated.