Const
Why an API key cannot be sent, or undefined: after trimming, a key with a control character (other than tab) or a character above U+00FF cannot be an HTTP header. A blank key is not a problem; it means "no key".
undefined
Why an API key cannot be sent, or
undefined: after trimming, a key with a control character (other than tab) or a character above U+00FF cannot be an HTTP header. A blank key is not a problem; it means "no key".