8-10k if it is just writing the story (used to write scientific papers on limited time so I am used to the grind).
Quality wise around 700-1k per day.
What do I mean? Simple I check grammar multiple times and I re read my story to make sure if I missed a detail or if things make sense. Each time I check the quality of my work I have to rewrite many parts around 4 times until grammar makes sense, the story makes sense, and I am not repeating words or way of saying things often.
Personally, I think a good author should have 10 ways to say the same thing in a more elegant way without repeating words. Let's say you wrote: "he took a bite of his hamburguer". And 3 lines later for whatever reason you need to write the same thing (and somehow that bite is crucial to the storytelling).
You can't simply repeat it as is. Your reader will find it repetitive. So you have to look for a way to make it different, elegant, and not boring.
A quick example would be writing the bite of a hamburguer as: "He continued devouring the food on his plate, not minding the stares people gave him."
Take in mind this is an example and personally I would modify both sentences to seem more elegant but as a quick example I think it helps get my point across on how even if I can write a lot of words daily it doesn't mean they have quality behind them.
You have to edit your own work and proofread it. Which takes time. If you have an editor or a proofreader you can go way faster. But as a solo writer process slows a lot.
P.S. Doesn't help I am a paranoid person and I check gramatical errors like 50 times per chapter even if I don't find any more.
P.S.S when I write in forums and stuff I ignore all errors in my writing. My brain gets melted as it is when I work on my novel don't need my brain to work 24/7 when I relax.