Failed to update IP to via webhook widget

My Webhook setting:
URL: http://xxxxxxxxxxxxSomecodexxxxxxxxxx&myip=/pin/
CONTENT TYPE: text/plain

String value = XX.XXX.XXX.XX
I use Blynk.virtualWrite(V-Webhook, value);
And there is no response from server, I already handle with BLYNK_WRITE(V-Webhook).
If I change /pin/ to /pin[0]/, there is response from server, but it’s say IP update is difference from my value
The URL address, direct send from browser is working correctly. I think problem is size of value, is it right?
If I send GET method normally by some code direct from hardware, it work correctly