Hi Enes Bekar,
Collections field is a Multi-Reference Field in “Stores/Products” collection.
So you must use .include(“collections”) function in the code.
https://www.wix.com/velo/reference/wix-data/wixdataquery/include
import wixData from 'wix-data';
$w.onReady(function () {
wixData.query("Stores/Products")
.include("collections")
.find()
.then((results) => {
console.log(results.items)
})
});