Traveler and Witch's Eyes Endings

[Sirlion]

I tried unlocking these 2 endings for 2 hours now and I cant. I saw all short episodes (Stranger \ Stranger contd required too of course) loaded multiple saves and then started the Flowchart from 3,1 but I still have no choices whatsoever in that chapter.
I started the whole game again, no dice.
I have seen all endings except "Heroine" which I wanted to do last. Is it required to view the other two or not? Because no guide mentions this and at this point I have no idea what to do

[Angel ♥]

Personally, I just followed the guide here on Steam and that worked for me.
According to this walkthrough, finishing all other endings first does seem to be a prerequisite: https://otomekitten.com/tag/psychedelica-of-the-ashen-hawk-walkthrough/.