In the documentary Francesco that was released in Italy on October 21, a very brief segment apparently includes Pope Francis speaking about same-sex civil unions.
It appears clear from current media reports that the director of the film pieced together different portions of an interview from 2019, removing vital context, to create the impression that the Holy Father was promoting the idea found in the documentary. Media sources then reported the cobbled-together statements in the documentary at face value, creating great confusion. See https://www.catholicnews.com/questions-continue-around-films-use-of-popes-quote-on-civil-unions/ for a more detailed explanation.
Bishop Edward Burns adds, "We await an official statement from the Vatican on the film but know that our Holy Father has always strongly and consistently taught that marriage is between a man and woman for a lifetime. Church teaching remains that marriage is a sacrament and an indissoluble bond between one man and one woman as established by Divine Law. The Church will continue to preach and maintain this teaching."