Physical Therapy Billing Question

Very new to PT billing and need help with this scenario:

Medicare patient, Initial evaluation
Therapist billed 97001... I requested G codes and C modifiers
that I think is required for Medicare

Therapists states: "No functional test [written] performed to determine
G-codes. I did an evaluation/screening only and no plan of care to continue treatment. Patient is blind and severely cognitively impaired-no verbal or written communication possible. All information came from 2 transportation aides. He said he could determine codes by his estimation if needed.

How should this be billed to Medicare {Don't forget, I'm new to PT Billing}

Thanks

Physical Therapy Billing Question