Did all steps and ran debug. Here's what it says:
Spoiler:
calibre 3.38.1 embedded-python: True is64bit: False
Windows-10-10.0.17134-SP0 Windows ('32bit', 'WindowsPE')
32bit process running on 64bit windows
('Windows', '10', '10.0.17134')
Python 2.7.15+
Windows: ('10', '10.0.17134', 'SP0', u'Multiprocessor Free')
Interface language: None
USB devices on system:
(USBDevice(vendor_id=None product_id=None bcd=None devid=usb\vid_1949&pid_0331&rev_???? devinst=1),
USBDevice(vendor_id=0xcf3 product_id=0x36 bcd=0x1 devid=usb\vid_0cf3&pid_0036&rev_0001 devinst=2),
USBDevice(vendor_id=None product_id=None bcd=None devid=usb\root_hub20&vid8086&pid9c26&rev0004 devinst=3),
USBDevice(vendor_id=None product_id=None bcd=None devid=usb\root_hub30&vid8086&pid9c31&rev0004 devinst=4),
USBDevice(vendor_id=0x8087 product_id=0x8000 bcd=0x4 devid=usb\vid_8087&pid_8000&rev_0004 devinst=5),
USBDevice(vendor_id=0xc45 product_id=0x670b bcd=0x3262 devid=usb\vid_0c45&pid_670b&rev_3262 devinst=6),
USBDevice(vendor_id=0xc45 product_id=0x670b bcd=0x3262 devid=usb\vid_0c45&pid_670b&rev_3262&mi_00 devinst=7))
No disabled plugins
Looking for devices of type: MTP_DEVICE
List of WPD PNP ids:
[u'\\\\?\\usb#vid_1949&pid_0331#g0w0tc039015f4ll#{6 ac27878-a6fa-4155-ba85-f98f491d4f33}']
MTP device: \\?\usb#vid_1949&pid_0331#g0w0tc039015f4ll#{6ac278 78-a6fa-4155-ba85-f98f491d4f33}
{'device_version': u'1.0',
'friendly_name': u'',
'has_bulk_properties': True,
'has_storage': True,
'manufacturer_name': u'Amazon',
'model_name': u'Fire',
'protocol': u'MTP: 1.00',
'serial_number': u'G0W0TC039015F4LL',
'storage': [],
'type': 'media player'}
Not a suitable MTP device, ignoring
No suitable MTP devices found
Looking for devices of type: SMART_DEVICE_APP
All IP addresses {'{67C8AC13-5589-11E8-AE9B-806E6F6E6963}': [{'broadcast': u'127.0.0.1', 'netmask': u'255.255.255.255', 'addr': u'127.0.0.1'}], '{E76F35D9-4CF2-4246-857F-E07E0F9A0206}': [{'broadcast': u'192.168.1.92', 'netmask': u'255.255.255.255', 'addr': u'192.168.1.92'}]}
No device is connected
Looking for devices...
Devices possibly connected: None