Believe the union should be at the top left (not the way Jack Black wears his "most patriotic outfit of all times").
https://www.wikihow.com/Hang-an-American-Flag-Vertically
When hung on a window, wall, or door, the union should always be on the viewer’s left or the flag’s own right.
https://www.americanflags.com/blog/post/the-proper-way-to-hang-your-us-flag-vertically-at-your-home