type Config struct {
	// Email is the OAuth client identifier used when communicating with
	// the configured OAuth provider.
	Email string

	// PrivateKey contains the contents of an RSA private key or the
	// contents of a PEM file that contains a private key. The provided
	// private key is used to sign JWT payloads.
	// PEM containers with a passphrase are not supported.
	// Use the following command to convert a PKCS 12 file into a PEM.
	//
	//    $ openssl pkcs12 -in key.p12 -out key.pem -nodes
	//
	PrivateKey []byte

	// PrivateKeyID contains an optional hint indicating which key is being
	// used.
	PrivateKeyID string

	// Subject is the optional user to impersonate.
	Subject string

	// Scopes optionally specifies a list of requested permission scopes.
	Scopes []string

	// TokenURL is the endpoint required to complete the 2-legged JWT flow.
	TokenURL string

	// Expires optionally specifies how long the token is valid for.
	Expires time.Duration

	// Audience optionally specifies the intended audience of the
	// request.  If empty, the value of TokenURL is used as the
	// intended audience.
	Audience string

	// PrivateClaims optionally specifies custom private claims in the JWT.
	// See http://tools.ietf.org/html/draft-jones-json-web-token-10#section-4.3
	PrivateClaims map[string]any

	// UseIDToken optionally specifies whether ID token should be used instead
	// of access token when the server returns both.
	UseIDToken bool
}