How did the reformation begin in France?

In the 15th century, the Gallican Church was born in France. One year before the Reformation, in 1516, an agreement was concluded according to which the French king became the head of the Catholic Church in France, therefore, other religious trends could not arise in France, this was regarded not as a struggle against the church, but as against the king. Therefore, popular Protestantism was persecuted by Catholics, but often the Huguenots fought back.