Either you view LLM code as stolen, in which case you cannot get permission of the original owners, or you accept that LLM code is not copyrightable and has no original owners.
On the “stolen” side, so far the courts have not generally agreed with that perspective except in cases where there is actually an existing copyrighted work that the LLM output is substantially similar to.
On the not-copyrightable side, the direct output of an LLM is generally legally seen as not copyrightable, but significant human modification or editing/reworking/steering/compilation (as in compiling a bunch of LLM-generated fragments into a functional whole) is still likely to be copyrightable.
On the “stolen” side, so far the courts have not generally agreed with that perspective except in cases where there is actually an existing copyrighted work that the LLM output is substantially similar to.
On the not-copyrightable side, the direct output of an LLM is generally legally seen as not copyrightable, but significant human modification or editing/reworking/steering/compilation (as in compiling a bunch of LLM-generated fragments into a functional whole) is still likely to be copyrightable.