After implementing this, I am getting a 403 with or without an active API key.
Running this:
node /my/path/node_modules/@ta11y/ta11y -o output.log https://example.com
returns:
✔ Extracting content via headless chrome
extraction results { visited: 1, success: 1, error: 0, root: 'https://example.com' }
✖ Auditing extraction results
Auditing failed: Response code 403 (Forbidden)