JSON web tokens for google my business API

Job ID: 31451833

Budget: €30 – €250 EUR

I am looking to retrieve google reviews from google api into my web app.
I am using this documentation:
https://developers.google.com/identity/protocols/oauth2/service-account
I am required to send a JWT to the google authentication server to retrieve a token that is used to access the API, although I have no idea how to use base64 encoding to sign the jwt and have it ready for transmission.
Is this something you are capable of doing?
My web stack is frontend React/NextJS.
Related categories: JavaScript Website Design JSON