UnhandledPromiseRejectionWarning: ReferenceError: btoa is not defined

[yoonsio]

(node:93625) UnhandledPromiseRejectionWarning: ReferenceError: btoa is not defined
    at encode (/Users/me/workspace/wa-tunnel/node_modules/uint8-to-base64/cjs/index.js:8:3)
    at sendData (/Users/me/workspace/wa-tunnel/src/wasocket.js:37:26)
    at Socket.<anonymous> (/Users/me/workspace/wa-tunnel/src/client.js:61:11)
    at Socket.emit (events.js:400:28)
    at addChunk (internal/streams/readable.js:293:12)
    at readableAddChunk (internal/streams/readable.js:267:9)
    at Socket.Readable.push (internal/streams/readable.js:206:10)
    at TCP.onStreamRead (internal/stream_base_commons.js:188:23)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:93625) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
(node:93625) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

node: v14.21.3
npm: 6.14.18