You may want to record calls to be able to re-listen to them for quality assurance.
Part 1: Ensure you have call recording enabled.
Step 1: Navigate to Setting > Phone Numbers > Edit > and then check the call recording box.
Step 2: Click "Update" to save changes.
Part 2: How To Listen to Recordings
Step 1: Go to Contacts and choose the contact you wish to listen to a recorded call with.
Step 2: Click into that contract record. Within the contact recorded for that individual contact, the center panel of the contact page should display communication you've had with the contact- from texts to emails to calls.
Step 3: Recorded calls with feature a play button, and you can click that to listen within the contact record. You will also see a stop button, volume button, and download button.