Test automation is typically included in the Definition of Done (DoD).

Test automation is a best practice in SAFe and is typically included in the Definition of Done (DoD). The DoD ensures that all work is tested and validated before being considered complete. Including test automation in the DoD supports continuous integration, reduces manual testing effort, and increases the reliability of every increment.
Reference: SAFe 6.0 Website: Built-in Quality SPC 6.0 Guide: “Definition of Done includes automated testing to ensure built-in quality.”