Update ticket custom fields

Hello
I’m trying to use the REST API documentation to update custom fields from postman and I can’t get it to work.

https://developer.getawesomesupport.com/documentation/rest-api/update-ticket-custom-fields/

Could you give me a usage example?
The errors they are giving me are the following:
-REQUES:
{
“custom_fields”:{
“telefono”: “123456”
}
}
-RESPONSE:
{
“code”: “rest_invalid_param”,
“message”: “Parámetro(s) no válido(s): custom_fields”,
“data”: {
“status”: 400,
“params”: {
“custom_fields”: “custom_fields no es del tipo array.”
}
}
}
Thanks and regards

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