Use admin api to stop/start

Help
1

1. Caddy version (0.11.5):

2. How I run Caddy:

caddy -conf pinger.txt

and here is the config file

http://pinger.test.xxxxxxx.info:9060
{
  root /usr/local/caddies/
  log /usr/local/logs/pinger.log
  index index.html
}

a. System environment:

Linux

3. The problem I’m having:

I am trying to stop and start the server using API — Caddy Documentation
I have read a bit about admin but cant get that to work unfortunately
Getting the following error

pinger.txt:3 - Error during parsing: Unknown directive 'admin'
2

Caddy v1 (and Caddy v0 which you’re using) are no longer supported. Please upgrade to Caddy v2.