Refurbished iPhone SE needs a passcode?

Return the phone for a refund. Without the passcode, you will never be able to use the phone.

Never a great idea to buy a phone online, but if you must, make sure that you are will be getting an "unlocked" phone. Unfortunately, some phones that are advertised as "unlocked" are not.

Tip.....make sure that the phone powers on to the "hello" screen. Try real hard to buy a phone in person, not online.

If the page says Activation Lock, then return the device as it will not be usable.

Get your money back. it was not properly prepared for sale and is most likely activation locked, making it useless.