I will assume you use extra module for purpose customises on place order js
In module you need define file requirejs-config.js
path
app\code\YourVendor\ModuleName\view\frontend\requirejs-config.js
Content
var config = {
config: {
mixins: {
'Magento_Checkout/js/action/place-order': {
'YourVendor_ModuleName/js/action/place-order-mixin': true
}
}
}
};
file YourVendor_ModuleName/js/action/place-order-mixin
define([
'jquery',
'mage/utils/wrapper'
], function ($, wrapper) {
'use strict';
return function (placeOrderAction) {
/** Override default place order action */
return wrapper.wrap(placeOrderAction, function (originalAction, paymentData, messageContainer) {
//Your extras logic here
//Add extended functionality here
return originalAction(paymentData, messageContainer);
});
};
});