Problem with POST request

Problem with POST request

Hello!
Please, help me with my problem.
I have custom web-service (on my local server) and I'm trying to call it from Zoho custom function.
In Postman it works properly, but in Zoho I get response " {"responseText":"internal exception","responseCode":"-1"}"

My code from custom function:

header=map();
header.put("Content-Type","application/json");
header.put("authorization","Basic XXXXXXXXXXXX");
request="{\"SqlText\":\"select * from Customer\"}";
resp = postUrl(url,request,header,false);
info resp;

What I'm doing wrong?