found a solution myself, here's the guide:

1. Download SSL certificate from here: https://docs.aws.amazon.com/redshift/latest/mgmt/connecting-ssl-support.html

   • This is the URL: https://s3.amazonaws.com/redshift-downloads/amazon-trust-ca-bundle.crt
   • It will download amazon-trust-ca-bundle.crt on your PC
   • rename the file to amazon-trust-ca-bundle.pem

2. Make sure it's publicly accessible (Amazon Redshift Serverless > Workgroup configuration > <your-wrokgroup>)

3. Add this rule to your Security Group (Amazon Redshift Serverless > Workgroup configuration > <your-wrokgroup> > VPC security group)

4. Then once all of the above step is completed try to Authenticate again

This guy is amazing his video also helped me along: https://www.youtube.com/watch?v=22K0PxjwIa0