magento2.3 – How do i get the order ID and Order Subtotal in the credit memo page?

Im currently trying to write a piece of code that refunds an order and attach it to the “refund” button in the credit memo page using the “sales_order_payment_refund” event.

But, right now, I want to be able to get Order_ID and Order_Subtotal from the credit memo page of the order I have opened to proceed, how can I retrieve those 2?