Package JavaFX into an executable fat JAR with Maven not generating valid classpath [duplicate]

I am trying to package my JavaFX application into an executable fat JAR, but it never works. I have tried several guides found online including aswers here on SO but I had no luck. I can manage to set the main class correctly, but the class path is always missing, which then throws an error that JavaFx runtime components are missing. I am now using maven-shade-plugin (I have tried other plugins) and here is the configuration in pom.xml:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <executions>
        <execution>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <shadedArtifactAttached>true</shadedArtifactAttached>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <mainClass>com.sjsm.App</mainClass>
                    </transformer>
                </transformers>
            </configuration>
        </execution>
    </executions>
</plugin>

Edit: as requested in the comments I am adding 3 links I used and none of them worked. Also note I have tried other sources than these over the past 2 or so weeks.

link1 link2 link3