1）If your Mac shows Gitfos GFLP801/AM-243-BT States "Offline" or not display in“Printers&Scanners”, it means that Mac did not recognize the printer.
Please try to unplug and plug the USB cable the Mac computer side and the printer side.
Then restart the printer(power off then on).
2）If it is still not displayed in “Printers&Scanners”, we need to check the USB connection.
Connect the flash drive by using the USB adapter and check whether the computer can read the data.
Unplug the flash drive and replace it with the USB cable of the printer. normally, if the flash drive can be read on the Mac, that USB adapter can provide a stable data connection for the printer.
3）If it is still not displayed in “Printers&Scanners”, please contact our after-sales service.