Keycloak inactive when project deploy

Hi everyone, I have a problem when setup my spring boot war file to the digital ocean server.
First, I install Keycloak 11.0.0 and Tomcat 9.0.37. They both working. After my project deploys on tomcat, Keycloak becomes like this when I check status on the server.

I want to know whether it could be my project error or port error or some config need to change on Keycloak. Thanks.