"Why did I big get earned income credit on my 2019 retrurn?
That does not make sense--you have some typos.
Are you trying to ask why you did not get earned income credit on your 2019 return? If you qualify for that credit, the software puts it on your refund automatically. Did you have income earned from working? Did you enter any children as qualifying child dependents? Or do you meet the criteria to get EIC if you are single?
Try the Earned Income tool to see if you should get EIC:
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/use-the-eitc-assistant
https://ttlc.intuit.com/questions/1899157-what-are-the-qualifications-for-the-earned-income-credit-eic-or-eitc