It does not light either by pilot light switch or with a match

if the stove or fireplace doesn't have electronic ignition then yes its looking for a pilot lite I used to have a old water heater that did this , turns out the problem was defective gas regulator making the pressures go up/down also was leaking outside that's what made it noticable

You have a gas washing machine? If you are talking about a dryer, shut off gas valve, get a vaccuum and clean burner area well, then make sure connections are tight and the line to pilot light is not crimped, and hold match near pilot light while turning on gas.

A faint gas odor near an appliance may indicate that the pilot light has gone out. If the appliance has a pilot light and the odor persists after relighting, exit immediately, leaving doors and windows open as you exit. Do not open windows if they're not already open. Do not use your telephone or cell phone, operate any appliance, light a match or turn light switches on or off. Call your local gas supplier from a neighboring location.

The directions are on the inside cover of the water heater as well as on the paperwork you received with the unit.
If you have none of these, get the make and model number of the unit and look it up on the internet.
General directions to light a gas appliance:
1.Turn the switch to, "Off"
2.Remove the 2 panels at the base of the unit.
3 Identify the pilot device.
4.Get a long lighter or match on a stick that reaches the pilot.
5.Turn the gas knob to the, "Pilot" position
6.Light the match and put it next to the pilot while pressing down the knob
7. Keep the knob pressed for about 45 seconds after the pilot lights
8. Let go of the knob so it's in the, "up" position
9. Turn the knob to the, "On" position
-the water heater should fire up in under a minute.
10. Put the metal panels back into position.

Look up product manual on internet.
Look at label located inside oven door, and add .pdf to search parameter to help find manual.
Then read section about lighting appliance.

If power is out, then pilot will not have any gas >> if gas control is electronic.
Many electronic gas controls require electric power to operate circuit board.

In old days, you removed the bottom tray on oven to access burner and pilot orifice. Then you pushed down switch to release gas through pilot tube, and put lit match into the gas stream to light pilot. Hold down switch until pilot flame heated tip of thermocouple which caused magnetic switch to stay open inside gas control. Release switch and pilot stayed lit.

Safety concerns and vast advances in manufacturing cheapness have changed gas appliances so they are more inconvenient for do-it-yourselfers during ordinary power outage.
Cook hamburger over metal bucket with newspaper, and grease on newspaper burns enough to cook hamburger.
People always buy generators and flashlights, but nobody suggest buying barbeque briquets and starter fluid as way to keep warm and cook.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Hello and thanks for inquiring. Take the front covers off the inside unit. This is where you will find the Gas Valve. Next locate the pilot assembly. This can be done by following the thermocouple from the gas valve to the end where you will see a little v shaped piece. This is where the gas will come out. Turn the Gas Valve selector to PILOT. Depress the gas valve and use a match to light the pilot. Hold the valve down for 30 seconds. Then let up and to the gas valve to the ON position. The unit will come on and light and when the bonnet temperature reaches 180 degrees the fan will kick on. Hope this helps you.

I have experience with coleman furnaces installed in mobile homes. There is a red switch on the gas valve. Some models require you to slide the red switch to the top and hold. Holding is allowing gas to the pilot. You have to stick a long match,grill igniter, to stick through the inspection hole (a little flap or door to see inside the burner area) and hold the match over the pilot while holding the switch upwards at the same time. Others have a pilot selection on the gas valve which you slide the red switch to pilot and push down and hold while liting the pilot. You may need help with holding the door open while doing this. If you can you can use the copper line for the thermocouple to hold the door open for you. Good luck

get a long stick match, a flashlight remove lower inspection cover, find thermocouple and pilot light will be next to it,turn gas valve to pilot light and hold down,stick the match in by thermocouple till the pilot lights and hold valve down till pilot stays lit,this may take a minute or more,then release gas valve and see if pilot stays lit, if not retry,if it wont stay lit,the thermocouple is defective and needs replacement

YES YOU DO NEED MATCHES TO LIGHT THE PILOT IT IT DONT HAVE A AUTO PILOT AND IF IT DOES THEN YOU'LD HEAR IT CLICKING OR TRYING TO LIGHT IF NO CLICK THEN YES MATCHES WILL WORK TO LIGHT THE PILOT

Relighting Your Furnace's Pilot Light
- Turn off the gas at the main valve at your utility box - Wait five to ten minutes for gas fumes to waft away - Get a long match—yes, a fireplace match, not a standard match - Set the gas valve on your furnace to "pilot" - Press the red button as you hold the match to the pilot valve - Keep pressing the red button for 30-60 seconds so the pilot can heat the thermocouple. Release the button and see if the pilot remains lit - If pilot goes out, wait five to ten minutes and repeat the process - Once the pilot stays lit, turn the main gas valve back on - If the pilot light continues to go out, call a technician, who may need to adjust or replace your thermocouple or adjust your pilot