[Calgon]

That script uses zcmd, so you just need to replace

pawn Code:

if (strcmp("/text", cmdtext, true) == 0)

with

pawn Code:

CMD:text(playerid, params[])

Although you might want to change 'text' to something else, because I think '/text' is also used for SMSing in that script.

You might also want to take a look at this, the script uses that streamer for objects.