Implement in react

Hello, I am trying to implement fernet js into my react application but I get errors.

Uncaught (in promise) ReferenceError: Buffer is not defined
    at Object.validate [as decode] (urlsafe-base64.js:61:1)
    at Function.decode64 [as decode64toHex] (fernet.js:35:1)
    at new Secret (secret.js:4:1

Thanks!