Getting 502 Bad Gateway for vitalticks.in web sitae

I don't know your detailed environment, but the following official AWS documentation may be helpful.

[1] Troubleshoot your Application Load Balancers - Elastic Load Balancing
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-troubleshooting.html#http-502-issues

[2] Troubleshoot Application Load Balancer HTTP 502 errors
https://aws.amazon.com/premiumsupport/knowledge-center/elb-alb-troubleshoot-502-errors/?nc1=h_ls

Please refer to the above for troubleshooting.