Tomcat does not start, and reports Error: Application Server not specified. after checking, I found that although I followed the teacher’s steps, but the teacher did not import the local tomcat, it should already exist in the idea, and because I did not import it, I can not use it properly, I need to import the local downloaded tomcat

After importing the correct path, Tomcat can be enabled normally, because I have always added Tomcat plug-in to POM file, so I ignored this step.