English: Go to your <a href="%1$s" target="_blank" rel="noopener noreferrer">SparkPost account</a> or <a href="%2$s" target="_blank" rel="noopener noreferrer">SparkPost EU account</a> and verify that your API key is correct.
Dutch: Ga naar je <a href="%1$s" target="_blank" rel="noopener noreferrer">SparkPost account</a> of <a href="%2$s" target="_blank" rel="noopener noreferrer">SparkPost EU account</a> en controleer of je API-sleutel correct is.