Hi German,
If you don't have other independent CAN transceivers,and you also have two FRDM-KE06, of course you can use it.
Each FRDM-K64 need to connect one CAN transceivers.
About the connections, you can check the FRDM-KE06 board schematic.

You can remove R72, R74,then use the wire solder in R72 CAN_TX side, and another wire solder in CAN_RX R74 side.
Connect it to your FRDM-K64 CAN TX and RX pin, then connect two FRDM-KE06 board's CAN_H and CAN_L together.

Please note, you need to power on the FRDM-KE06 board, because CAN transceivers need the power.
Wish it helps you!
Have a great day,
Kerry
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