You can add the scala maven plugin reference in the pom.xml as below
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.2</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
<configuration>
<scalaCompatVersion>2.11</scalaCompatVersion>
<scalaVersion>2.11.8</scalaVersion>
</configuration>
</plugin>
</plugins>
</build>
Once you do this and build you will be able to see the option of the scala class.