Go to your <a href="{bbackup_94402fb9ba80f392e0976ece85f92b2b876bfcaed8d83250cc06083f7139c7d9}1$s" target="_blank" rel="noopener noreferrer">SparkPost account</a> or <a href="{bbackup_94402fb9ba80f392e0976ece85f92b2b876bfcaed8d83250cc06083f7139c7d9}2$s" target="_blank" rel="noopener noreferrer">SparkPost EU account</a> and verify that your API key is correct.