Step 1 (of 8):

Select the device settings icon.

Step 2 (of 8):

Select Cellular within your device settings.

Step 3 (of 8):

Verify that your cellular data is on.

Proceed to Cellular Data Options.

Make sure your LTE/VoLTE and Data Roaming are turned on.

Step 4 (of 8):

Select Cellular Data Network.

Step 5 (of 8):

Under the MMS section, select APN and enter wholesale.

Step 6 (of 8):

Select MMSC and enter: 

http://wholesale.mmsmvno.com/mms/wapenc

Step 7 (of 8):

Select MMS Max Message Size and enter: 1048576.

Step 8 (of 8):

Return to the home screen to save.
Turn the device off and back on.