26 Then God said, “Let Us make man in Our image, according to Our
likeness. They will rule the fish of the sea, the birds of the sky,
the livestock, all the earth, and the creatures that crawl[i] on
27 So God created man in His own image; He created him in the image of
God; He created them male and female. (Genesis 1:26-27)
The confusion is in verse 27, which says him then them.
Adam was created in the image of God, which is the "He created him". Then in chapter 2, Eve is created by removing one of Adam's ribs.
At the time when Adam was created, there was no Eve yet, and Adam was created in God's image. At that point in time, only Adam was created in God's image, and Adam constituted a complete image of God.
However, after Eve was split off from Adam, Adam and Eve - male and female - collectively constitute the image of God. Neither man nor woman as individuals hold a complete image of God. God can create people by Himself, but it takes a pair of people - a man and a woman - to create more people (scientific pretensions set aside).
So only Adam was made in God's image, but he did not retain that complete image for long; once Eve came on the scene, he was part of a team.