You will need tech stream to program the new keys. You will find tutorials here and on You Tube showing you how.
If 4 keys are already stored in your computer it will be more difficult because you will need to go through an elaborate procedure to remove them before you can add more. This involves paying an online service to obtain a special key code which you will need to enter through tech stream to erase the codes. This procedure is also used when you replace your ignition lock. Details are on You Tube.
Alternative-
If you have a working key, see if they can cut you a key from an earlier Toyota which does not have the chip in it to save you a few dollars. Once you have verified it will turn the ignition and the door, un-clip the sensing coil which surrounds your ignition lock, tape you old key to it and bury it inside your steering column. If you are concerned someone could use that key to steel you car, cut the head off the key and tape the head only to the coil. This is a trick used often when remote starters are installed.
You will never need to deal with a chipped key or program.