Uncaught Error: Call to a member function getQuote() on null

[Sunil Patel]

Hello @tvgarden

you need to create the on change event of that element and fire your js code.

[tvgarden]

This didn't work:

$( 'input[name="postcode"]' ).on( "change", function() {
console.log(getPostcode());

});

[magemodule]

Please don't instantiate the $objectManager directly. Magento has been recommending against this for a long time now. Also, as per Magento docs, rather than referencing your class name as a string, e.g. '\Magento\Checkout\Model\Cart', instead reference classnames like this \Magento\Checkout\Model\Cart::class

[Rakesh Jesadiya]

You need to keep below js into your js file,

$( document ).on( "change",'input[name="postcode"]', function() {
	console.log(getPostcode());
});