If you like a smooth textured ice cream, add the poppy seeds at the beginning. If you prefer little whole crunchy poppy seeds, add them at the very end.
If you don't have a high speed blender, first grind the chia seeds (and you can also grind the poppy seeds as well) before mixing with the milk. If you do have a high speed blender, pour the coconut milk and chia seeds (and gelatin, if using) in the blender and let sit while assembling the other ingredients.
Add all the ingredients to the blender, blend on high until all the seeds have been pulverized, about a minute. Chill and follow the instructions for your ice cream maker.
If you don't have an ice cream maker, freeze the mixture in a container (something rectangular). When frozen, dump out the ice cream and cut into chunks. Put the chunks in a high speed blender (I don't know if a food processor would work) and blend, tamping down to keep the thick mixture moving. Pour back into the container and freeze again.
Alternatively, freeze mixture in container and whisk (then stir) every half hour until frozen.