How to Assign an App to a Space on Mac

How to assign an app to a Space on a Mac: right click the Dock icon, choose Options, then pick All Desktops, This Desktop, or None. It sticks.

1. Open the space you want to use. Switch to the desktop where the app should live. Press Control and the Right Arrow until you land on it, or open Mission Control and click its thumbnail. The assignment you are about to make refers to whichever space is showing now.
2. Open the Dock icon options menu. Right click the app icon in the Dock, or hold Control and click it. In the menu that appears, move to Options. A submenu opens with the Assign To choices at the top. The app needs to be running or kept in the Dock.
3. Choose an Assign To option. Pick All Desktops, This Desktop, or None. All Desktops shows the app windows on every space. This Desktop binds new windows to the space you are on. None removes any assignment and lets windows open wherever you happen to be.
4. Confirm the assignment holds. Quit the app and open it again from another space. An app assigned to This Desktop pulls you back to its home desktop instead of opening in front of you. The assignment survives quitting the app and restarting the Mac.
5. Undo or change it later. Return to the Dock icon, open Options, and choose None. The app forgets its home. If you want it on a different space instead, switch to that space first, then choose This Desktop again from the same menu.