How do we provide credentials for a Composer entry in BitBucket Pipeline

[Mike McGonagle]

We use a commercial library via Composer and need to provide credentials in order to download and install the package.  How do we do this in a Bitbucket pipeline?  We are getting the following error:

- Installing XXXXXXXXX (2.0.4): Downloading (connecting...)Downloading (0%) Downloading (75%) [Composer\Downloader\TransportException] The URL required authentication. You must be using the interactive console to authenticate