VEVOR 32 x 30 x 2.5 Inch Washing Machine Pan 18 GA Thickness Galvanized Steel Heavy Duty Compact Washer Drip Tray with Drain Hole & Hose Adapter

What is the size of the drain hole on the pan, not the adapter, the hole on the metal pan itself?

I cant use the drain can it be sealed off?

Is there a bigger size