I looked MKRWAN 1310's pinout diagram (https://content.arduino.cc/assets/Pinout-MKRwan1310_latest.pdf) where Li-Po 3.7 V battery is connected to JST S2B-PH-SM4-TB(LF)(SN) type of battery connector.
According to technical specs, the operating voltage of the circuit is 3.3V.
Is it safe to connect 3.7 V Li-Po battery to MKRWAN 1310 as the pinout diagram shows? Isn't there need for an external step-down voltage regulator (from 3.7 V to 3.3V) or is it built-in to MKRWAN 1310?