NFRs — Non Functional Requirements (qualities of a system like Scalability, Security, etc) are constraints of a system once built and in place. For example: Architecture team determines that Amazon Web Services (AWS) should be the one to go with (this is alignment with ‘Scalability’)… then they make this as one of their ASRs (Architecturally Significant Requirements). Once this ASR is in place, it constraints upcoming functional requirements that use web services … AWS will be used instead of another web services from somewhere else.
NFRs are part of the Definition of Done (DoD).
NFRs are initially enablers along the architecture runway… supporting / enabling a functional requirement to its fruition.
NFRs and Enablers are like the devil and angel on your shoulders as you build functionality of your system.