index.js

console.log('Loading function');

exports.handler = async (event, context) => {
    if(process.env.KeyName1 === 'true') {
        console.log('value1 =', event.key1);
        console.log('value2 =', event.key2);
        console.log('value3 =', event.key3);
    }
    return process.env.KeyName2;
};