Hi....try this and let me know if it works: Transfer Audio Files from a Windows PC:
Connect the LG Tribute to your computer using the USB cable
When prompted, tap "Media sync (MTP)". Otherwise, swipe the "Notification" bar down and tap the option from there
In the AutoPlay window on your computer, click "Open device to view files using Windows Explorer"
Launch a second Windows Explorer window and navigate to where the desired audio files are stored on your computer
Copy the desired audio files to your phone. NOTE: audio files should be transferred in the "Ringtones", "Notifications", "Music" folders etc.
After the transfer is done, click the "Safely Remove Hardware" icon located in the system tray
Click "Safely Remove Mass Storage Device" and press "OK" to confirm
Safely disconnect your smartphone from the computer
Changing the Phone Ringtone:
Ensure that the audio files you wish to use have been transferred in the "Ringtones" folder
While on the home screen, tap "Apps"
Tap "Settings" and go to "Sound"
Swipe under "Ringtone & Notifications" and tap "Phone ringtone"
Select the ringtone you want to use. NOTE: items that have been recently transferred in the "Ringtones" folder should be listed under My Ringtones.