if your talking about the item called upgrade than you can use it evolve porygon into porygon 2 when you link trade it.
Chat with our AI personalities
Get a porygon 2 make it hold the upgrade and then trade. -Hope I Helped!
in the silph co. building.
upgrade to the national dex and see and catch every Pokemon
Give porygon an upgrade and trade it it evolve it. And of course you have to trade it back. Try this in Pokémon go!
its in the team rocket warehouse on five island