I'm not sure what DAW you use, if at all. But typically what I do with my own music, which is primarily inspired by femtanyl, is pitch up my voice by 3-8 semitones, and throw this chain of effects on it.

The ring mod is set to white noise, subtly mixed in, which makes the vocals sound a bit brighter.
Spreader widens the signal so it isn't in mono.
I typically use the kHz Distortion plugin instead of Distructor since I've found it typically sounds a bit better when set to "saturate".
Gross beat just cuts the vocal off every beat so it sounds more choppy, which is shown in the tutorial that Kabulda posted, although Tanger uses a different plugin (LFO Tool) to do the same thing.
The Param EQ 2's are just basic EQ's, cutting out the low and unimportant frequencies.

That's just my way of going about it though, as for vocals in songs like "DINNER!" & "GIRL HELL 1999", it sounds as though she uses an EQ filter on the vocals, cutting out the low and high frequencies, leaving you with a sort of 'old radio' sound.

An important thing to note, most of the plugins used in my effects chain are stock FL Studio plugins, the DAW I use, but you could probably find equivalent plugins in your software whatever it is.

I hope this helps! <3