[Jstylezzz]

pawn Код:

if(strcmp(cmdtext, "/i use", true))

If the strings are the same, strcmp returns 0. What you do is call the command if the returned value is 1.
Try

pawn Код:

if(!strcmp(cmdtext, "/i use", true))
    //rest

Placing a '!' before strcmp should work.

OR

You can place a == 0 behind it. It would look like this

pawn Код:

if (strcmp("/i use", cmdtext, true) == 0)
 //rest

I hope this helps you further