@eduardo7: Welcome to the community. I translated your message and hope you are trying to do the below:
"Good afternoon ,
if someone could help me with a json format error.
I am creating a client with certain parameters but when sending, I get the
message (Malformed JSON string)."
Can you please provide more details? Please ensure that the params are correct. Also Ensure you have added the correct “Content-Type” in the headers.
El mensaje de error significa que el formato en el que está pasando los datos es incorrecto, lo que me hace pensar que pasarlo en este formato podrĂa ayudar.