When therapists are not accepting new clients, their calendar will not display any available times. If you're open to waiting 4+ weeks to see a therapist, you could contact them by email and request to be added to a waitlist.

Some therapists choose not to have their phone availability listed on their page. If their profile states that they’re accepting new clients but there is no phone consultation booking system, try contacting them via email anyway.

Related:
How do I find a therapist with available appointments?
How do I contact a therapist?