How to make a partial postage refund on item that has paid and been dispatched

[61stephenuk]

Find the order  in your seller hub, you’ll see ‘start refund’ on the dropdown menu
Enter the reason you’re processing the refund
Set the amount of money you’re refunding, either by item or by order
Once the right amount is entered, hit ‘send refund’ and you’re done
You’ll then see the amount you refunded show up on the order details.

Seller Hub

[the.collier.sisters]

I'm sorry, I cant make head or tail out of this new set up, I cannot see anything referring to refund on the drop down 'order'. Unfortunately I am not a techi person and I'm really struggling with this new set up!