Had to look up the dialogue on page 21 and it seems like the meaning got a bit warped.
大人になって、冒険者になって。。。もし手助けしてほしい時は、言いなさい
(when you) become an adult, (when you) become an adventurer... a time comes when you want (our) assistance, just say the word.
Disclaimer: I'm shit at japanese so maybe...