Hi @dhamini.sugendran ,
The message says what it means 
For now, you would need a license to be able to use custom keywords.
BUT: From what I could read in the forum here Question about missing functionality since 9.x.x - #5 by philipB this feature should be coming back for free in the upcoming new 10.0.0, due for release shortly. So perhaps stay tuned for that version ?