Unable to host a backend server on aws ec2

Could you provide more information? What is the application? What is stopping it from working? Are there any error messages? What are you trying to do?

Hii the putty I installed it's not connecting to ssh while I am using the auth option and using the private key of ipv4 it's just showing opening the terminal and showing connection timed out

There are many, many questions (and answers) here on re:Post about troubleshooting connectivity to your instance.