Connecting multiple CAN devices via I2C / CAN splitter

Hello. I want to connect two Here3 GPS via the CAN port to Pixhawk. I’m using an I2C / CAN splitter to connect both. Both GPS work fine individually one at a time. I changed the uavcan.node_id for one of the GPS from the default value of 0 to 1. I have enabled all the CAN drivers and everything else in the DroneCAN setup documentation page. Is there anything else to do? How does the Pixhawk know what node_id to expect for each GPS? Is there a similar setting to how you set the I2C address for each I2C device in the params? Or does it automatically identify all the devices connected to the CAN bus?