PHP API cannot execute commands

By the way, I need this three commands to execute:

First: Disable SSTP
interface sstp-client set 0 disabled=yes

Second: Monitor if SSTP is disabled
interface sstp-client monitor 0 once

Third: Enable SSTP
interface sstp-client set 0 disabled=no

Fourth: Monitor SSTP
interface sstp-client monitor 0 once


This is what I need, but I cannot understand router OS php api syntax…

Thanks