I prefer use hiragana for how to read kanji, so I would say:
ひらがなでかいてもらえますか。
It's the translation, however, we have other ways of say it because of the politeness.
ひらがなでかいてもらえませんか。
ひらがなでかいていただけますか。
ひらがなでかいていただけませんか。
(It's the politest between these four.)
I hope this was helpful.