How do I install TestFX in a maven project?

Question

<dependencies>
    <dependency>
      <groupId>org.openjfx</groupId>
      <artifactId>javafx-media</artifactId>
      <version>15</version>
    </dependency>

    <dependency>
      <groupId>org.openjfx</groupId>
      <artifactId>javafx-controls</artifactId>
      <version>15</version>
    </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>org.testfx</groupId>
      <artifactId>testfx-junit</artifactId>
      <version>4.0.16-alpha</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

I have added these dependencies on my maven project, installed maven wrapper and I'm using VSCode. The last dependency gives me an error that says "The element contains information about a dependency of the project." Is there anyways I can fix this?