Send data (json format) to webpage node red

Hello ,
I want get value from devise and send on webpage json format
I need to create a page web like there

Use the http request node with msg.payload as the json to send.

from the node info page
If msg.payload is an Object, the node will automatically set the content type of the request to application/json and encode the body as such.

you can send me an example ?

What device are you wanting to get data from?

Do you mean you want the device data to be available from an endpoint like in your picture?