It doesn't matter during germination. Its best to germinate on a plate with tissue paper (kitchen roll) under and over the seeds. Wet the kitchen paper and wait until you get a 2 cm tap root out of the seeds. Then plant into damp (not too wet) soil. You dont really need to put them too far down into the soil. Be sure you keep the seeds in a warm place while they are germinating. Germinating in soil will give you much more losses of seeds over time. Just makes sense to do it on a plate and then plant them. You should see the tap root in 2 days or so.

Put them in the soil and when the seeds open and you see the first 2 leaves then light is important. Keep the light as close as possible without burning to prevent stretching. Keep the nodes 1 inch apart.

Hope this helps

Take care