Test Email not sending

Replies: 0

Hi,

When I try to send a test email, I keep on receiving this error log

Versions:
WordPress: 5.8
WordPress MS: No
PHP: 7.4.18
WP Mail SMTP: 3.0.3

Params:
Mailer: sendinblue
Constants: No
API Key: Yes

Debug:
Email Source: WP Mail SMTP
Mailer: Sendinblue
[unauthorized]: Key not found

Any idea on how to fix this issue?