Could not fetch chain ID. Is your RPC URL correct?

[the-emerald]

Seems like I'm unable to set up MetaMask to use the proxy.

New RPC URL: http://localhost:9545
Chain ID: 1

$ yarn start --rpc https://eth-mainnet.alchemyapi.io/v2/[REDACTED]
yarn run v1.22.17
warning ../package.json: No license field
$ tsdx build && node dist/index.js --rpc https://eth-mainnet.alchemyapi.io/v2/[REDACTED]
@rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.
@rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.
✓ Creating entry file 678 ms
✓ Building modules 1.6 secs
Listening on port 9545

MetaMask version: 10.9.2
Browser: Firefox 97.0 (64-bit)
OS: Windows 10