As @keunes observes, no setting is required. That said, many people (including myself) have observed that AntennaPod won’t resume if the interruption (such as a phone call) takes more than 30 seconds.
This was originally believed to be related to Bluetooth or certain peripherals, but it turns out it can happen when just using the phone directly. I don’t know if this is an Android issue, an AntennaPod issue, or something else.