I am using ES256 algorithm and how do I try it in jwt.io?

Question

I'm generating a token using the header, payload and private key I got from apple. But how do I test in jwt.io if this is the valid signature? Because jwt.io wants public and private keys. I do not have a public key and it is not correct to write the private key there?

My example token is like this eyJhbGciOiJFUzI1NiIsImtpZCI6ImFiYyIsInR5cCI6IkpXVCJ9.eyJpc3MiOiIxMjM0IiwiaWF0IjoxNjUyMzQwOTYzLCJleHAiOjE2NzIzNDQ1NjMsImF1ZCI6ImFwcHN0b3JlY29ubmVjdC12MSIsImJpZCI6ImNvbS5saXZlIn0.pzhtpscducF_J5FG7nX6D_02mqHrsF2epRTv5dtHzahWPiQic5wOdJLtWwbPOWOo4Eq7ZBjaEacOyWhDKKdrWA

When I write this to jwt.io, I get an "Invalid Signature" error because it asks for public and private keys. What should I write in the public and private key parts?

SOLUTION I generated public key using private key and it said Signature Verified

openssl ec -in AuthKey_123ABC456.p8 -pubout -out AuthKey_123ABC456_public.p8