Currently, there is not a way! I can write up a post about how best to get the endings if that'll help! For now, the first available ending is basically don't engage with the stranger (so ignore him, etc.) in the beginning, also don't go to the bus stop right away (so wait here at the start), and then don't check belongings. Otherwise, it does show up as a choice if you make certain decisions but only one forced way to get the ending.
The second available ending you can get is easily gotten by not hitting the "Make him elaborate" choice--basically, never trying to learn WHY you're where you're at and just accepting well, this is where you're at and the second ending will show up. Not choosing the elaborate choice will let you choose between two of the endings (so the first available one and the second available one). Like the first ending, there is only one way to get this as a forced ending which is a little more complex to get, but I can include how to in my write-up.
I hope this helps! And I'll see about writing up a short thing this weekend to help guide players who want to make sure they get the endings!
The last ending you simply keep trying to learn what happened and don't be complacent. Head to the bus stop, check belongings, ask his name first, make him elaborate when you can, keep thinking of the party, question the stranger when you can, stay, answer the phone, and then convince him there's another way. Those should be enough to get you the third ending.
If you check the downloads, you should have access to the .pdf of the ending guide if you need a little more guidance!