Is Jesus the fulfillment of the law & the prophets?

Yes. "For the law was given through Moses; grace and truth came through Jesus Christ." John 1:17.

This was possible since Jesus was the forgiveness of our sins (Matthew 26:28; Hebrews 12:24; Ephesians 1:7). "She will give birth to a son, and you are to give him the name Jesus, because he will save his people from their sins." Matthew 1:21.

But these are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name. John 20:31.

That if you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised him from the dead, you will be saved. Romans 10:9. For it is by grace you have been saved, through faith--and this not from yourselves, it is the gift of God. Ephesians 2:8-9.

The prophets of the Old Testament (OT) prophesied of Jesus Christ (Jude 1:14-15, John 11:51-52), which Jesus fulfilled. (See Matthew 13:35; Luke 18:31, 22:37, 24:44; John 19:24; Acts 1:16)

Take Isaiah 61:1-2 in the OT for example, which was fulfilled in the New Testament (NT) by Jesus in Luke 4:17-22:
The scroll of the prophet Isaiah was handed to him. Unrolling it, he found the place where it is written: "The Spirit of the Lord is on me, because he has anointed me to preach good news to the poor. He has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to release the oppressed, to proclaim the year of the Lord's favor." Then he rolled up the scroll, gave it back to the attendant and sat down. The eyes of everyone in the synagogue were fastened on him, and he began by saying to them, "Today this scripture is fulfilled in your hearing." All spoke well of him and were amazed at the gracious words that came from his lips.