If you want to do it in JavaScript as blockly doesn’t support it then it is like this:
var logger = Java.type('org.slf4j.LoggerFactory').getLogger('org.openhab.rule.' + ctx.ruleUID);
var Exec = Java.type("org.openhab.core.model.script.actions.Exec");
var Duration = Java.type("java.time.Duration");
var TOPIC = null;
var PAYLOAD = null;
var rfinput = itemRegistry.getItem('RFBridgekitchen_Receiveddata').getState().toString();
switch(rfinput) {
//row 3 green and switch is on S
case 'BB369A':
events.sendCommand("Lightsshedinandoutside_Shedlights", 'ON');
logger.info('Shed lights ON');
break;
//row 3 red and switch is on S
case 'BB3692':
events.sendCommand("Lightsshedinandoutside_Shedlights", 'OFF');
logger.info('Shed lights OFF');
break;
default:
}