How can free will exist when God hardened Pharaoh’s heart?

Devoted Christian here working my way through the entire Bible in a year and I’m in Exodus right now (NLT). It says multiple times that the Lord says to Moses “I will harden Pharaoh’s heart so show my great works.”

My question is: doesn’t that violate free will? I’m not questioning God at all. Obviously it’s due to a misunderstanding on my part. Just curious what you guys think. Thanks!