Technical question

Hi!

I recently purchased a second hand 3ds XL and I'm loving it.

Only problem is when I go to set it up to my home wifi it asks for the 4 digit code which the previous owner didn't give me. I could ask them for it but it was an eBay sale and I strive to avoid potentially awkward scenarios...

What are my options? I'm well into a Pokemon x play through so don't want to do anything that will cause me to lose any save data on that game, any other suggestion would be greatly appreciated