if you look at the Schematic it seems the SAMD21 Cortex®-M0+ and SARA-R4 pins are directly connected to the headers so I would think it's like the rest of the MKR family - don't go over 3.3V
if you look at the Schematic it seems the SAMD21 Cortex®-M0+ and SARA-R4 pins are directly connected to the headers so I would think it's like the rest of the MKR family - don't go over 3.3V