Protein powder isn't essential when it comes to smashing your goals and burning fat. If you're not keen on using it, it's not a problem to leave this out of your meals and snacks. However, this may mean that some of the recipes are no longer accurately tailored as they won't contain the same level of protein. It could also impact the taste and texture of certain meals, and so you may have a little less choice in recipes.
If you're breastfeeding, we would always encourage you to check that your GP is happy for you to have protein powder.