How so? Is the 2013 that different from the 2015? Don't they all have chips?
It seemed to me cheap way was to buy key that could unlock doors but would not start car for about $5. There might be a way to keep the key with the chip in it inside car at all times close to ignition and then cheap keys you make will work.
For me, the best I could do was have two keys made (seemed better than one b/c I had to pay an hour labor regardless to get programmed), was to order these (below), go to locksmith (I went hoping he had software to program) to cut $2.5 each (could also let dealer do) and then pay dealer to program next oil change.
When I bought there was a non logo one at tad cheaper but 2 keys with tax and shipping came to about $62.
I complained to dealer that over $100 for an hour of labor was sort of rediculous for plugging something into a computer while doing an oil change, he gave me a discounted rate of $70 to program both keys.
That was the best I could do but I'm happy to have 4 keys now.
Dealer needed to have both keys to program so that gave me some reassurance that getting extra keys now, before lose one, was the best way to go.
It may not be possible to program backup keys with only one key. In that case, may want to have locksmith make 4 keys for you and tape original key with chip to steering column and use spares.