Public IPv4 address not working

Verify that there is a route to the Internet Gateway in the route table of the subnet where EC2 is located.
Check the inbound rules of the EC2 security group to see if the necessary communications are allowed.
When accessing EC2 with a browser, http must be allowed in the inbound rules of the security group.
I think you need to check the network ACLs to see if they are being denied inbound or outbound.
Also, make sure that the web server is running in EC2.

For additional troubleshooting, please refer to the following documents.
https://repost.aws/knowledge-center/ec2-instance-hosting-unresponsive-website