I see a problem with the concept of "not truth", because just as I define truth as what it is, I cannot define "not truth" as what it is not, because what it is not does not exist, and I cannot have a concept for something that doesn't exist. So everything that exists must be true, because "not true" does not exist, and something cannot be "not true". This does not mean that "falsehood" does not exist, only that it makes us have to redefine it, because falsehood cannot be "not truth", because it does not exist, and it must be something that is true at some point. I like to say that the false is simply things as they seem to be, and all the false things that many people have come to believe, is simply because it seems to be true for them, because subjectively, from their perspective, it seems to be true for them, but it's just an opinion. In this sense, falsehood cannot be "not truth", but it is what is subjectively true, although not objectively true. Unlike what we usually call truth, which is objectively true, out of appearances.

In this way, I am not saying that what we subjectively perceive through our senses (OPINION/QUALIA) is "not true", but that it is true although only subjectively.

I also see the danger of considering any knowledge as "irrefutable facts" because, one is always human and there is a considerable margin of error, so that what we consider "facts" can also end up being opinions, that's why I am more on the side of falsificationism and I tend more than anything to consider justified knowledge as "not refuted", rather than as "absolute truth".