demi-glaze on auburn

Hello forum. My hair is naturally light brown and ashy, and I recently went deep auburn after a lifetime of blonde hair. I love the glossy results that my colorist got with Redken Shades EQ (she first used a brown filler and then used an auburn mix over it). I want to do this myself (to save money and also because I will be traveling). What should i use to get the same result at home? Also, I have long straight hair just below my chest. I think she mixed colors to get this result. Also, how many bottles will I need? Thanks so much!!!