While in your game, click the back button which opens up the menu. Then click on set time portal and then click on one of the slots to save the state.
To load the save state, from the same menu click on Travel and then choose your state. (your game needs to be loaded for the save state to load I’ve found)
Awesome. Thank you.
How do I use save states?
When I click on save it just goes back to the game and there’s no load button.