Can't find variable: Buffer

[Sonwanseo]

Version of EOSJS
22.1.0

Describe the bug
When I use PrivateKey, I got an error.
The error message is "ReferenceError: Can't find variable: Buffer".
This error causes because there's no buffer import statement.

(The Buffer is node.js built in object, so I don't understand why this error caused...)

To Reproduce
If you need the example, please refer to my test project
Clone my project, and execute 'yarn start' in terminal
Please check 'src/PrivateKey.ts' file

Expected behavior
No Error !

Screenshots

Desktop (please complete the following information):

• OS: macOS Monterey 12.2.1
• Version
  • Node.js 16.14.2 (LTS)
  • Expo SDK 44
  • TypeScript 4.3.5

Additional context
Sorry for my bad English,,