Let me just clear up the lack of knowledge being displayed here about CRT by explaining how it works in terms anyone--well most people--can understand.
CRT is derived from Critical Legal Theory that came from Critical Pedagogy.
Critical Pedagogy is a radical Leftist education theory that holds all education is indoctrination and propagandization. That is, the purpose of education is to teach politically correct thinking to the student such that they will reject by critically examining what they are later told as being inconsistent with their indoctrination.
Critical Legal Theory extended this to the law by holding that there are favored and dispossessed groups in the way laws are structured.
Kimberly Crenshaw a radical Leftist Marxist who invented the academic theory of Intersectionality-- Digressing for a moment:
Intersectionality looks at the social and economic identity of an individual or group and seeks to determine that individual's or group's privilege or repression / discrimination compared to other individuals or groups.
That explains that.
Anyway, Crenshaw took her idea of Intersectionality, and combined it with classical Marxist didactic on class struggle and Critical Pedagogy / CLT to come up with CRT.
CRT holds that you are a member of a group or class that is either oppressor or oppressed on the basis of race. Everything you do is looked at through the lens of racial content. Groups that are deemed oppressors based on their perceived or claimed privilege (from Intersectionality) are racists under CRT. Oppressed groups cannot be racist as they are the victims of racism, not producers of it. Only groups deemed oppressors can be racist.
In classic Marxist theory this would be the bourgeois and wealthy versus the workers and poor. The bourgeois and wealthy are oppressors, and the workers and poor are oppressed. There is no exception made for either group. That is, if you are poor you cannot oppress others, only be oppressed.
Thus, in CRT all Whites are racists (eg., oppressors). At the same time, all Blacks are not racists and cannot be racist because they are oppressed, not oppressors. That's one example of CRT applied.
So, by extension, you get the radical Leftist idea of White Privilege. All Whites are racist. Or, America is a racist nation. It must be in CRT as it is majority White and they are the oppressors. CRT would argue that simply "Browning" America will shift things in favor of the oppressed races and overcome the racism of Whites.
In terms of K - 12 education, this is applied using the methods of Critical Pedagogy to indoctrinate and propagandize the students into accepting this version of racism created out of CRT. The application is usually subtle and done within each lesson plan and inserted into textbooks. There is no in-your-face--well, for the most part--application as those using CRT and Critical Pedagogy know that will just meet resistance rather than acceptance.
The examples I gave, like those from the Manhattan Institute, show that students are widely exposed to ideas that CRT would seek to indoctrinate them with. That, in turn, shows that CRT is indeed being used in K - 12 education widely as a teaching methodology / pedagogy.