'PASSWORDLESS_TOKEN_GENERATION_ATTEMPT' is not working. 

Hello developers, thank you for this pakage.
I have a doubt regarding 'PASSWORDLESS_TOKEN_GENERATION_ATTEMPT' setting. it is used for limiting the attempt to generate token using 6 digit token. am i right? if yes then, it is not working . is there any solution to make it work. And no then, what is this setting for??