The Civil Constitution of the Clergy was a law passed during the French Revolution which attempted to make subordinate the Catholic Church in France to the French government.
Among other things, it required that Catholic priests and bishops be elected locally (which included non-Catholics) in an attempt to abolish the authority of the Pope to appoint clergy in France.
According to https://en.wikipedia.org/wiki/Civil_Constitution_of_the_Clergy, The Pope condemned those who took the oath and went as far as saying that they were absolutely separated from the church. citation , but no page(s) indicated.
QUESTION: Where (papal encyclical, I presume) may I find Pope Pius VI's aforementioned condemnation of those clergy who took the oath required by the Civic Constitution of the Clergy?