screen.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ComboBox?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane prefHeight="484.0" prefWidth="550.0" xmlns="http://javafx.com/javafx/15.0.1" xmlns:fx="http://javafx.com/fxml/1">
   <children>
      <Label layoutX="129.0" layoutY="41.0" prefHeight="31.0" prefWidth="292.0" text="Label" />
      <Button layoutX="197.0" layoutY="300.0" mnemonicParsing="false" prefHeight="26.0" prefWidth="156.0" text="Button" />
   </children>
</AnchorPane>