Can I change my Talabat menu or prices from Get Menu?

No. Your menu and your prices inside a delivery app stay in that app's own portal, where you set them today. What we send the apps is availability: when you switch a dish off on the Menu page, or the kitchen marks it sold out, the connected apps that accept it are told. Whether each app took the change is written into What the apps said. The Orders from delivery apps tab in the docs covers sold out pushes.