Does the BigTreeTech (BTT) Octopus support 48V?

According to the BTT Octopus Pro GitHub repository the BigTreeTech Octopus mainboard V1.0/V1.1 does NOT support 48V stepper drivers.

If you need 48V stepper drivers, you need to use the Octopus Pro board. Note that they are not 100% pin compatible. Check the link for details.