You just copied my script, changed the burn time (which you made way too high), and renamed a few variables. Either give me credit for everything, or take it down.

My script: 

https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=17793

The source was this:

local element1 = elements.allocate("FEYNMAN", "NPLM")
elements.element(elements.FEYNMAN_PT_NPLM, elements.element(elements.DEFAULT_PT_BCOL))
elements.property(elements.FEYNMAN_PT_NPLM, "Name", "NPLM")
elements.property(elements.FEYNMAN_PT_NPLM, "Description", "Napalm")
elements.property(elements.FEYNMAN_PT_NPLM, "Colour", 0x850000)
elements.property(elements.FEYNMAN_PT_NPLM, "MenuSection", 5)
elements.property(elements.FEYNMAN_PT_NPLM, "Gravity", .5)
elements.property(elements.FEYNMAN_PT_NPLM, "Flammable", 0)
elements.property(elements.FEYNMAN_PT_NPLM, "Explosive", 0)
elements.property(elements.FEYNMAN_PT_NPLM, "Loss", 1)
elements.property(elements.FEYNMAN_PT_NPLM, "AirLoss", .5)
elements.property(elements.FEYNMAN_PT_NPLM, "AirDrag", .01)
elements.property(elements.FEYNMAN_PT_NPLM, "Advection", .01)
elements.property(elements.FEYNMAN_PT_NPLM, "Weight", 50)
elements.property(elements.FEYNMAN_PT_NPLM, "Diffusion", 0)
NPLMUpdate = function(i, x, y, s, n)
local clife = tpt.get_property('life', x, y)
if clife > 1 then
for cx = -1, 1, 2 do
for cy = -1, 1, 2 do
tpt.create(x + cx, y + cy, 'fire')
end
end
tpt.set_property('life', clife - 1, x, y)
elseif clife == 1 then
tpt.set_property('type', 0, x, y)
elseif s > 0 then
for cx = -1, 1, 2 do
for cy = -1, 1, 2 do
if tpt.get_property('type', x + cx, y + cy) == 4 or tpt.get_property('type', x + cx, y + cy) == 49 then
tpt.set_property('life', 500, x, y)
return true
end
end
end
end
end
tpt.element_func(NPLMUpdate, tpt.element('nplm'))
NPLMgraphics = function(i, colr, colg, colb)
return 1,0x00000011,255,125,0,0,255,125,0,0
end
tpt.graphics_func(NPLMgraphics, tpt.element('nplm'))

By the way, you forgot the graphics function.