[RedFusion]

pawn Код:

if(strlen(inputtext))

Checks if the length of the string isn't 0

pawn Код:

if(strlen(inputtext) > 0)

Checks if the length of the string is above 0

pawn Код:

if(strlen(inputtext) != 0)

Same as the first alternative

All of these alternatives work for what you want to achieve
https://sampwiki.blast.hk/wiki/Strlen
https://sampwiki.blast.hk/wiki/Control_Structures#Operators