How to send data to the Server from Widget?

Hello everyone!

So I want to send data to the server from a widget. So the OnDrop function has an Operation pin and I get the payload from it, then cast to an Object reference, that contains the information about the item, I want to remove from the inventory. So I want to send that Object reference to the server. I tried that I send it to the PlayerController with a RunOnServer event, but When it comes to the RunOnServer event it gets invalid. How can I send it to the server correctly?