peering between a Lightsail instance and my default VPC

Hello.

Lightsail VPC peering cannot be configured from the Network tab.
You must configure it using the steps outlined in the documentation below.
https://docs.aws.amazon.com/lightsail/latest/userguide/lightsail-how-to-set-up-vpc-peering-with-aws-resources.html

To enable VPC peering between your Lightsail instance and your default VPC, you need to follow a specific process that's different from what you're looking for in the Networking tab.

Here's how to properly enable VPC peering for Lightsail:

1. Open the Lightsail console
2. Choose Account from the top navigation menu
3. Select the Advanced tab
4. Look for the AWS region (us-east-1 in your case) where you want to enable VPC peering
5. Enable VPC peering for that region

VPC peering in Lightsail is enabled at the region level, not at the individual instance level, which is why you don't see the option in the Networking tab of your instance. Once you enable VPC peering for the region, all Lightsail instances in that region will be able to communicate with resources in your default VPC.

You can verify if the VPC peering was successful by:

1. Opening the VPC console
2. Choosing Peering connections in the side menu
3. Checking if there's a peering connection between your Lightsail VPC and your default VPC

Remember that after enabling VPC peering, you'll need to:

1. Update route tables in both VPCs to direct traffic between them
2. Configure security groups to allow traffic between the resources

Also, ensure that your default VPC exists in the region and that the CIDR blocks of the Lightsail VPC and your default VPC don't overlap, as this is a prerequisite for successful VPC peering.
Sources
Community | Connecting Lightsail to AWS Services
Connect Lightsail resources to AWS services using VPC peering - Amazon Lightsail
prerequisites to ensure vpc peering | AWS re:Post
How VPC peering connections work - Amazon Virtual Private Cloud