How can I encode a string in Typescript when implementing Figma plugin

Question

I'm implementing a Figma plugin, and I need to encode a line of text in base 64. I've found that I can implement that function with

I've tried

Buffer.from('STRING').toString('base64')

but Buffer is not recognized in @figma/plugin-typings

This project is not a Node.js project but a Figma plugin, so I wonder if there's another way to implement this or a package that is available for Typescript.