How can I translate Different languages in to English in R?




I want to do sentiment analysis on customer reviews but they are in different laguages some are in German, some are in spanish, and many others.

I tried to use translateR package but I didn’t get desire output. I think I didn’t generate my google API key properly

Can anyone please tell me how can I convert multiple language in to English and How can I generate Google translator API without Billing?

Please give me some suggestion.
Thank you