If you follow the code then you will see there is 3 layers. about php-ga4 HOT 1 CLOSED

Okay, you need to first populate an item, then you need to make your event and pass the item to that event, and finally add it to the Analytics call.

$item = AlexWestergaard\PhpGa4\Item::new() // This is a CLASS not an ARRAY
    ->setItemId('blabla')
    ->setCurrency('usd')
    ->setPrice(60)
    ->setQuantity(1);

$event = AlexWestergaard\PhpGa4\Event\BeginCheckout::new()
    ->{your params here}
    ->addItem($item); // <--- You need to add the item to the EVENT, not ANALYTICS

$analytics = AlexWestergaard\PhpGa4\Analytics::new('id', 'secret')
    ->setClient('bla')
    ->addEvent($event); // You need to add the EVENT to ANAYLTICS, where in EVENT contains ITEMS

$analytics->post(); // This you want a try-catch around as is throws on errors, it returns void

You can NOT add Items to ANALYTICS and you can not pass ARRAY as argument as it is validated on items->toArray() that all REQUIRED parameters are set inside of src/Helper/IOHelper.php.

--- EDIT

The reason it is separated is because you might want to sent multiple events with the same items, this way you can easliy add the items to multiple events by reference.

--- EDIT 2

This also enabled that the same events can be sent to multiple Analytics instances, for example some e-comm websites have a global tracker for all shops and then a separate tracker per shop.

from php-ga4.