Via "get my payment" it's.gov, it said cannot determine eligibility. I didn't file a tax return in "18 or "19 and am working currently. How do I receive check?

[Critter]

If you are required to file a 2018 or 2019 tax return then do so ASAP. 

If you had no income for 2018 or 2019 then you can register to get the stimulus payment :  https://www.irs.gov/coronavirus/non-filers-enter-payment-info-here