I need a German Sponsorship Letter

hello, I am a student from Nigeria who have been admitted to study at one of the German colleges in Germany. As a Visa requirement for studying in Germany, I am searching for a German sponsorship letter from anyone who is resident in Germany. It could be a Nigerian or a German who is resident in Germany. Basically, The Sponsor letter is about saying you are financially capable of covering my expenses in Germany. Note, you are not responsible for expenses, as i am financially capable of taking care of myself and i would also do linear jobs when schooling in German to earn more income. Basically, The sponsorship letter is just a referral or Guarantor letter. I am responsible person and i am also of good conduct as can be clearly seen in my reviews as an employer on the freelancer platform. Thanks