Jesus said anyone who wants to come after him must deny himself and take up what?

Answer: His cross

In Mark 8:34 Jesus said a follower must deny himself, take up his cross and follow him.

“Then Jesus called the crowd to Him along with His disciples, and He told them, “If anyone wants to come after Me, he must deny himself and take up his cross and follow Me.”— Mark 8:34 (BSB)