You seem to be asking if concepts allow ADL if a type fulfilled the concept.
Remember, these declarations are declared to be equivalent (per 14.10.2):
void f(C &c);
template<typename T> requires C<T> //Needs () if `C` is a function
void f(T &c);
These declare the same function. Indeed, 14.10.2 goes on to express a highly complex set of rules to explain exactly how this breaks down.
But in any case, applying a requires clause to a function does not affect how it is looked up.