Check yourself before you destructure yourself.

destructure-nested-object.js

const data = {
    entry: [
        {
            messaging: [
                {
                    senderId: 1,
                    payload: {
                        text: 'hello'
                    }
                }
            ]
        }
    ]
};

Promise
    .resolve()
    .then(() => {
        for (const entry of data.entry) {
            for (const {
                // We extract `payload` by destructuring an element from the `entry.messaging` Array,
                // but because it's an Object which in turn is destructured, `:` must be used.
                // Because `:` in a destructuring statement assigns to a variable with a different name
                // than the (destructured) object property, i.e. `payload`, that variable is NOT defined.
                payload: { text }
            } of entry.messaging) {
                if (payload) { // throws an error because payload is not defined
                    console.log(`message text: ${text}`);
                }
            }
        }
    })
    .catch(err => console.log(`${err}`)); // ReferenceError: payload is not defined