Key fob replace

It has to be a key for the identical car and then you need the Prius software on a laptop and connect it to your car with a mini vci cable.
See this youtube vid:

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See other threads about TIS Techstream software (available on Ebay)

 

If you are trying to program a used fob. Then the ONLY way is.

Either call a locksmith so he can use his T-code or mvp pro type machine or similar to program.

Or

You can use techstream to do an all keys lost procedure which will reprogram your original key and your 2nd fob you are trying to program. This requires a reseed process. Locksmith will do a similar process but depending on his programming setup his equipment will generate the correct seed code from the hardwares proprietary software etc.

It’s possible to use and program a used fob but this is the only ways. None of that chicken dance shit will program a used fob.

I do these types of programming for people about 2-3 times a week sometimes.

 

You need help from a "professional".
If not a dealer, then a locksmith who does that kind of automotive keys.