Je (vais) donnerai

At the moment i’m learning that “je donnerai” means “i will give”. I was listening to a podcast and i heard the guy say “ je vais donnerai”.

When i put both things into translate they both translate to “i will give”.

The vais part isn’t necessary afaik now. but is it used often by french speakers? And why add vais if it isn’t necessary?

Thank you for your answers.