Do you need a business plan?
Or maybe you are asking what the heck is a business plan?
Of course it’s not required to start and grow your business. It could be helpful.
It all depends on what sort of business you are building. It can help you get some clarity, and clarity is power.
The main point, is to not let not having one stop you from starting. Develop your plan as you go is a fine alternative, but you may eventually need one to help you focus on what you are offering. Your plan includes how to create a profitable business, and in the beginning or even if you are underway, you may not be certain of this, and chances are it will need adjustment. If you want a resource for how to write a business plan here is a good resource: