How to add HTML text into Books note field

I would like to add HTML formatted text into the note field in a Zoho Books estimate.

I am creating the estimate in a function in CRM.

Adding <br> or \n have no effect. The API will also just accept a string as parameters.

CRM Code:

response = invokeurl

[

type :POST

parameters:parameters.toString()

connection:"crm2books"

content-type:"application/json"

];

EDIT:

This works:

newLine = hexToText("0A");

string = "A" + newLine + "B";