Telephone 99441-99443 do not have prolonged service codes, per the correct responses by @jmph0916
From CMS FAQs, section P, question 32:
Question: How should practitioners bill for audio-only services that last longer than 30 minutes?
Answer: During the PHE for the COVID-19 pandemic, Medicare has added to the list of telehealth services CPT codes 99441–99443, which describe audio-only phone visits with practitioners who can independently bill for E/M services, and CPT codes 98966–98968, which describe audio-only phone visits with practitioners who cannot independently bill for E/M services (for example certain therapists, social workers, and clinical psychologists). CPT codes 99443 and 98968 describe 21–30 minutes of medical discussion, respectively for each practitioner type; but there are no CPT codes available to describe medical discussions lasting longer than 30 minutes.
It is possible a commercial carrier has set a different policy, but I have not seen any.