thank you @Terdious for this very detailed article and very
thank you @cicoub13 for the info about data sharing
and thank you @pierre-gilles (but your solution isn’t for me, but you didn’t know my need 
)
The need: I need to know the exact rainfall that falls in my garden, because I run a « remote vegetable garden », I’m often away, it’s good if the vegetable garden is watered if it’s been very hot, or if it’s not watered even though 10 mm of rain has already fallen.
With Meteociel, I look at the readings from 2 stations less than 5 km from the house, and sometimes the differences are crazy
When I say it’s too expensive, it’s not so much the price of this item, it’s the whole home automation setup that starts to get expensive.
What also tires me is having to put my data on the Internet
Equipment-> Internet ← Me who wants to read my data
whereas we should be able to do this
Internet ← Equipment ← Me who wants to read my data
If the service is canceled or becomes paid, I could still query my data.
pff it’s complicated, isn’t it?