They want to know you are legit and paying taxes. Try to formalise and show that you do this. I don't know stipulations for that embassy but meeting the criteria for London was very hard, I had to supply alot of difficult paper work. Give them as much as you can!
accountant letter, in date work contract, proof of funds, covering letter from client / agency, schedule of work letter, photo, proof of address, it was quite a lot from London embassy tbh