The drying time depends by how thick the dough is. Control from time in time. If it’s dry on both sides than it’s ready, if only on the top change sides and give another 15-20 minutes to the other side. At 100°C it can’t burn, so don’t worry too much to overdo.
As seeds you can use flax seeds, pumpkin seeds, sunflower seeds or what kind of seeds you like. You can also admit the seeds if you don’t like them or have a digestion problem with them.
If you want a rustic taste add also some pepper and/or curcuma.
For a sweeter taste add two dates.