Why am I getting an error when trying to run WildFLy on Intellij?Application Server was not connected before run configuration

Question

I'm creating a Wildfly + Maven Restful API in Intellij, everything seems fine except at run time the program crashes saying "Application Server was not connected before run configuration stop,Unable to ping server at localhost:8080". I'm following a tutorial step by step at https://courses.bekwam.net/public_tutorials/bkcourse_wildfly_restful_devenv.html. So the problem is probably with WildFly. Please give me a detailed guide on how to sort this.

Here's my code: package com.example;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
import java.util.HashSet;
import java.util.Set;

@ApplicationPath("/api")
public class Api extends Application {

    @Override
    public Set<Class<?>> getClasses() {
        Set<Class<?>> set = new HashSet<>();
        set.add( HelloWorld.class );
        return set;
    }

}

package com.example;


import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

@Path("/hello")
public class HelloWorld {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String getMessage() { return "Hello, World! 3"; }
}

POM.XML file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>PracticeProj</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <dependencies>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jaxrs</artifactId>
            <version>3.6.2.Final</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.2</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>


</project>