Eberspacher BN2 gas heater
VW bug, beetle

The BN2 can be difficult to light, that is because it only has a glow plug and does not have spark ignition like the BN4.

If the heater will not start:
Assuming the heater is not broken in any way there are two likely reasons.  No fuel, or the heater is flooded.  If you have fuel coming out of the
end of the hose at the heater, then it is probably flooded.  Unplug the fuel pump and try and start.