Update EC2 security group

In order for EC2 instance to be able to access Aurora database, you need to update security groups and add default security group (the one used when you created Aurora database) to the EC2 instance.

On the AWS Console page, click on the EC2 link under the Compute section (or search for EC2).

Select DotNet5Graviton2 instance, go to Actions -> Security -> Change security groups.

Security group

Select default security group, click Add security group and then save changes.

Security group