Help integrating Java with Azure or Amazon

Hi devs! My team is having trouble deploying the front and backend in both Azure and AWS. I think it's a code issue, not a cloud configuration issue. Has anyone else had a similar experience? How did you resolve it? Please help. I feel it's common to have Java projects with these clouds.

The error is a 404; it can't find the files to start the services when refreshing or due to inactivity.

Thanks.