How to customize ChatBot Slack message?

I want to publish ECR vulnerability scan results to my Slack channel. I successfully configured EventBridge rule for AWS Inspector Scan and I'm receiving the messages in Slack.

However the message looks pretty unusable:

Inspector2 Scan | eu-central-1 | Account: 123456789012
Inspector2 Scan
Related resources  
• arn:aws:ecr:eu-central-1:123456789012:repository/my-app

It doesn't show the most important information, which are the findings, e.g. from the SNS message:

{
    "version": "0",
    "id": "739c0d3c-4f02-85c7-5a88-94a9EXAMPLE",
    "detail-type": "Inspector2 Scan",
    "source": "aws.inspector2",
    "account": "123456789012",
    "time": "2021-12-03T18:03:16Z",
    "region": "us-east-2",
    "resources": [
        "arn:aws:ecr:us-east-2:123456789012:repository/amazon/amazon-ecs-sample"
    ],
    "detail": {
        "scan-status": "INITIAL_SCAN_COMPLETE",
        "repository-name": "arn:aws:ecr:us-east-2:123456789012:repository/amazon/amazon-ecs-sample",
        "finding-severity-counts": {
            "CRITICAL": 7,
            "HIGH": 61,
            "MEDIUM": 62,
            "TOTAL": 158
        },
        "image-digest": "sha256:36c7b282abd0186e01419f2e58743e1bf635808231049bbc9d77e5EXAMPLE",
        "image-tags": [
            "latest"
        ]
    }
}

Is there any way to preprocess the final Slack message to include some additional information from the SNS event?