In the "Email address" field, enter the email address that you have connected in "Senders" on SendinBlue
In the "Email password" field, enter the password for your email. Important! if you use an email provider, then generate and use an App password. Example with Google WorkSpace mail:
Go to SendinBlue website > Settings > Your Senders and Domains
Next, go to SMTP & API > SMTP TAB > CREATE A NEW SMTP KEY
Create your SMTP key, copy it, and paste it into the SMTP password field
In the SMTP username, SMTP host, and SMTP port fields, enter the data specified in SendinBlue