Is there a way to input a family tree that is in Gedmatch or Ancestry.com?
Gedmatch is a DNA comparison tool. I believe you mean GEDCOM. This Help Article shows the process: https://www.familysearch.org/en/help/helpcenter/article/how-do-i-upload-my-gedcom-file
Please check to see if the people are already in the tree first, especially older ancestors -- many are already here and GEDCOM imports just create duplicates. Also check that the tree you're importing is properly sourced. There's a lot of trash on Ancestry, GENI, MyHeritage, etc.