251. In discussing the dignity and mission of the family, the Synod Fathers observed that, “as for proposals to place unions between homosexual persons on the same level as marriage, there are absolutely no grounds for considering homosexual unions to be in any way similar or even remotely analogous to God’s plan for marriage and family”.
Not every union, among same-sex attracted persons or heterosexuals, aligns with God’s plan. Some people seeking marriage or union are of no religion. Some who have religion have other purposes, unions of convenience. To be sure, we’ve seen this in marriages through the centuries: arranged marriages among royalty and aristocracy, unions for pragmatic purposes. The Biblical example of the one bride wed to seven brothers. Sometimes, the aspirations for a union “outside of God’s plan” are a matter of practicality, as determined by the people involved.
It is unacceptable “that local Churches should be subjected to pressure in this matter and that international bodies should make financial aid to poor countries dependent on the introduction of laws to establish ‘marriage’ between persons of the same sex”.(Relatio Finalis 2015, 76; cf. CDF, Considerations Regarding Proposals to Give Legal Recognition to Unions between Homosexual Persons (3 June 2003), 4)
For your reference, remember that Amoris Laetitia is online here.