code: public OvhMailDomain2Service fax_customDomains_POST(String domain) throws IOException {
  		String qPath = "/me/fax/customDomains";
  		StringBuilder sb = path(qPath);
  		HashMap<String, Object>o = new HashMap<String, Object>();
  		addBody(o, "domain", domain);
  		String resp = exec(qPath, "POST", sb.toString(), o);
  		return convertTo(resp, OvhMailDomain2Service.class);
  	}
docs: Create a custom domain for your fax services
  
  REST: POST /me/fax/customDomains
  @param domain [required] The custom domain of your fax services