How do I use an LEDs wired for 277V AC on a 12V DC power supply?
Measure the input AC voltage.  I doubt the input must be 277VAC.  Many LED drivers specify an input voltage from 100VAC to 277VAC.  277VAC is associated with a commercial electrical service of 3 phase 480/277 where the 277 can be used single phase.

The voltage of a constant current driver will adapt to the forward voltage (Vf)  of the LEDs being driven.If there were 80 LEDs each with a Vf of 3.0V, the output would then be 240V. 

A 12V inverter may work fine.  IF you measure 277VAC at the input then try using 120/240VAC before buying an inverter.

Keep in mind you may be able to use an inexpensive DC-DC LED driver that may likely cost less than an inverter. Although 240V is too high for the common solutions.