Seems I may have enabled the VoLTE option on my LG V40 by:Create a folder within internal storage called " enable_ue " (without the quotes)." Go to Phone app, dial *#546368#*405# (Note all the bold typeface characters are required - Seems to vary by model - I found using 405 got me straight into the hidden menu - While the phone is a V40, its specific model is LM-V405EBW....guess where 405 comes from!). (Note all the bold typeface characters are required - Seems to vary by model - I found using 405 got me straight into the hidden menu - While the phone is a V40, its specific model is LM-V405EBW....guess where 405 comes from!). Then go to Settings / "Network & Settings" / "Mobile networks" where I found the new VoLTE option present and already selected! Maybe there's a way in the hidden menu to enable the earthquake warning messages but it was not obvious.