CRT is derived from Critical Pedagogy through Derrick Bell's Critical Legal Theory. It was invented by the Marxist Communist Kimberley Crenshaw using those as its basis. CRT was combined by her theories on Intersectionality.
In a nutshell, CRT is warmed over neo-Marxism. Under CRT, racism is endemic to particular groups and races based on their economic status and assumed privilege within society. This race replaces economics as a class structure. So, Whites are oppressors and racists by simple virtue of their economic status and assumed privilege. Being White--in and of itself--makes you a racist even if you individually are not. At the same time, being in a minority group assigned less status like being Black makes you the oppressed target of racism and hence, you cannot be racist even if by your actions and words are clearly so.
Individuality plays no role in CRT. It is the group collective you are put in that matters. It's no different than being in the proletariat and working class versus the bourgeoisie and monied class. Warmed over Marx.
So, in application, CRT would seek to identify each person's status and class, assign to them a role of oppressor or oppressed, and then proceed to indoctrinate them on that basis. You're White? You must acknowledge your racism and atone for your sins. Black? You are oppressed and you need to rise up against your oppressors. Again, classic Marx.
That in a nutshell is what CRT is. Critical Pedagogy, the original basis is no different. It started with Paulo Freire's Pedagogy of the Oppressed where the argument is made that education should be indoctrination into groupthink and being good revolutionaries of the radical Left among the oppressed (peasants, workers, and dispossessed of society). This was glommed onto by radical Leftist Marxists and turned into a theory of how education should proceed.
Bell's Critical Legal Theory derives from that that there are groups that are oppressed and benefit from the way laws are structured. Same thing, different setting.