How to send ESC/POS commands on phonegap

Question

I am programming a Phonegap App that sends printing to a thermal printer using Bluetooth

I am using phonegap-bluetooth-plugin and print normally

But when using ESC commands, they are being printed with the text.

I can print using the code:

bluetooth.write(onSuccess, onFailure, "Hi Dani, How are You?");

I do not know how I should include the ESC commands in this code... Ex. Trying to select the size of the characters

var data_print = "1D 21 02"+"Hi Dani, How are You?";
bluetooth.write(onSuccess, onFailure, data_print);

As would be the correct way to insert the ESC commands in this code? Any feedback is appreciated! Tks !