I'm looking for a word describing the act of administering therapy or of giving therapy to someone.
The job of a therapist is to ________
A therapist is
one specializing in therapy; especially : a person trained in methods of treatment and rehabilitation other than the use of drugs or surgery · a speech therapist
Therefore, the job of a therapist is to treat patients:
4 : to care for or deal with medically or surgically · treat a disease
Or, the job of a therapist is to rehabilitate patients:
2 b : to restore or bring to a condition of health or useful and constructive activity