Customize language from English to Japanese of points & rewards for Shopify store

I need Shopify certified developer especially who knows language conversion. This job is to change a point-granting application that is Loyalty, rewards & referrals that is not support Japanese. We would like to change English to Japanese with Loyalty, rewards & referrals. We can translate English into Japanese for you if you give us the English text lists-up if you don’t use any app but translation app must be free or very low cost.