If you look 点ける up on WWWJDIC, you would notice it has 'uk' tag, which stands for 'usually kana' and indicates words that have kanji for them but are usually written in kana. Both variations are correct but Japanese people usually write it as つける. That's why he also writes it in kana.
If you look 点ける up on
If you look 点ける up on WWWJDIC, you would notice it has 'uk' tag, which stands for 'usually kana' and indicates words that have kanji for them but are usually written in kana. Both variations are correct but Japanese people usually write it as つける. That's why he also writes it in kana.