Spring Boot applications are slightly different to tradition Java web applications (or Jakarta EE applications) in that they by default create a JAR file with embedded server in it, rather than traditional WAR file that is deployed on a standalone Servlet container or fully featured Java EE server.
Alternatively, Spring Boot applications can be packaged as WAR files as well. Follow the instructions in Spring Boot documentation how to do this.
The main differences between JAR and WAR packaging are as follows:
No need for a server binary install, a Java Runtime is all that is needed.
Bigger package size.
a separate Java Servlet container needed
free choice of servers, including Jetty, Tomcat, WildFly, GlassFish, and others
smaller package size
See Using Spring Boot Properties for additional details.
You can read more about Spring applications and how to deploy them at the official Spring website.