Почему JavaFX выдайт ошибку при подключении скрипта js к FXML?

<?language javascript?>
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.VBox?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.canvas.Canvas?>
<VBox alignment="CENTER" spacing="20.0" xmlns:fx="[http://javafx.com/fxml](http://javafx.com/fxml)"
      fx:controller="com.df.sandbox.HelloController">
    <padding>
        <Insets bottom="20.0" left="20.0" right="20.0" top="20.0"/>
    </padding>
    <Label fx:id="welcomeText"/>
    <Button text="Hello!" onAction="buttonClick"/>
    <Canvas fx:id="mainCan"/>
    <fx:script>
        buttonClick = () => {
            welcomeText.setText("Oh, yea")
        }
    </fx:script>
</VBox>

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

    <groupId>com.DF</groupId>
    <artifactId>sandBox</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>sandBox</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <junit.version>5.8.2</junit.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-controls</artifactId>
            <version>18</version>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-fxml</artifactId>
            <version>18</version>
        </dependency>

        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.10.1</version>
                <configuration>
                    <source>18</source>
                    <target>18</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.openjfx</groupId>
                <artifactId>javafx-maven-plugin</artifactId>
                <version>0.0.8</version>
                <executions>
                    <execution>
                        <!-- Default configuration for running with: mvn clean javafx:run -->
                        <id>default-cli</id>
                        <configuration>
                        <mainClass>com.df.sandbox/com.df.sandbox.HelloApplication</mainClass>
                            <launcher>app</launcher>
                            <jlinkZipName>app</jlinkZipName>
                            <jlinkImageName>app</jlinkImageName>
                            <noManPages>true</noManPages>
                            <stripDebug>true</stripDebug>
                            <noHeaderFiles>true</noHeaderFiles>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>