Created a bucket through Lightsale - can't see it in S3

Lightsail buckets differ from regular S3 buckets in that they have several features that are not available.
Therefore, they are not displayed in the bucket list from the S3 console and can only be checked from the Lightsail screen.
You will need to create a regular S3 bucket to configure the URL you shared.
https://docs.aws.amazon.com/ses/latest/dg/receiving-email-permissions.html

Normal S3 bucket creation can be done in the manner described in the following document.
https://docs.aws.amazon.com/AmazonS3/latest/userguide/create-bucket-overview.html