Confirmation is one of the three sacraments of initiation into the Catholic church. It is a fulfilment of the sacrament of Baptism through which we have been led towards a desire to live out our Christian faith. It fully initiates us into the life of the Church. Conversion to Christ is a gradual process to which Confirmation gives added strength. The confirmed person is strengthened by God’s grace through the Holy Spirit for the lifelong journey of which this sacrament marks the beginning.
“by the sacrament of Confirmation, [the baptized] are more perfectly bound to the Church and are enriched with a special strength of the Holy Spirit.” (1285) Catechism of the Catholic Church
Because this sacrament signifies being fully initiated and involved in the life of the church, those wishing to take the sacrament must enter into it of their own free will.
You can read more about the sacrament of Confirmation here