So many options that would do the trick! Let’s play a little game of “What if…?”
pour out the melted wax so the wick melts and burns more fuel, more quickly
add more wicks (e.g. some candles have 3 or more wicks), which then melts and burns it faster
use a fatter wick (similar effect to using multiple wicks)
use a different kind of wax (some will burn more slowly than others) or eliminate the wax entirely and use only a liquid fuel
add an accelerant, such as alcohol, gasoline, kerosene, whale oil, etc. that would burn hotter and accelerate the burning of the wax
heat up the candle itself (e.g. put it into a warmer environment), so the flame has to expend less energy to melt and then burn the wax
put the candle near a fan (more air flow will result in a faster rate of combustion)
increase the concentration of oxygen in the environment (this will also increase the rate of combustion); be careful not to go above a certain concentration of oxygen, or you can turn a spark into an explosion (see Apollo 1 disaster)
increase the atmospheric pressure (again, see Apollo 1 disaster)