I cannot possibly state for certain how Judas was judged by God into Heaven or Hell, No one knows that but God. !
Judas may be in Purgatory, but that is not for me to make an absolute assertion on.
"If any man's work is burned up, he will suffer loss, though he himself will be saved, but only as through fire." (1 Corinthians 3:15)
To be saved, you must believe in the Lord Jesus Christ (Acts 16:31). However, that's not all. Sacred Scripture clearly shows other things you must also do to be saved:
You must endure to the end. Matthew 10:22, Matthew 24:13, Mark 13:13.
You must accept the Cross (suffering). Matthew 10:38, Matthew 16:24-25, Mark 8:34, Luke 9:23, Luke 14:27.
You must be baptized with water. Mark 16:16, Titus 3:5, I Peter 3:20-21.
You must be a member in God's true church. Acts 2:47.
You must confess your sins. James 5:16, I John 1:9.
You must keep the Commandments of God. Matthew 5:19-20, Matthew 7:21.
You must heed the words of St. Peter, the first Pope. Acts 11:13-14, Acts 15:7.
You must eat the flesh and drink the blood of Jesus Christ. John 6:51-58, I Corinthians 10:16, I Corinthians 11:23-29.
Our justification comes from the grace of God. Grace is favor, the free and undeserved help that God gives us to respond to His call to become children of God, adoptive sons, partakers of the divine nature and of eternal life. CCC 1996, John 1:12-18, John 17:3, Romans 8:14-17, 2 Peter 1:3-4.
Angel