mac address setting

I have tens (60) of w5100s hats (which I plan to use for PICOs) connected to a switch.
I configured each with its IP but then figured out that all of them have the same MAC address, which causes many TCP retransmission.

How can I set each w5100s module with its unique MAC address?

I found this python class but failed to use it.
def mac_address(self, address):
“”“Sets the hardware MAC address.
:param tuple address: Hardware MAC address.
self.write(REG_SHAR, 0x04, address)