How old are your eggs? They can be 2-3 weeks old before you put them in the incubator although your hatch rate will be lower. If you need to, you probably could use a heat lamp but it’s going to be a real pain in the ass. You’ll have to look up the temperature the eggs need to be at, as well as the humidity and make a container with a tiny amount of ventilation to keep those two things from fluctuating. Humidity won’t matter as much as heat will. If it goes up or down too much for too long everything dies. You’ll also have to rotate the eggs by hand every day. If somehow you work it out and they are ready to hatch, the humidity has to increase. If it doesn’t the shells will be too hard and they’ll all die of exhaustion trying to get out. Chances are the heat lamp will kill more than aging the eggs a few more days. Best tip I can give is to look up the lockdown period and learn about it. My first hatch was a challenge because I opened the incubator during hatch to remove chicks. Real stupid on my part. Probably killed 5-6 birds. Good luck