Questions about taxes

So I received a notice from RITA saying that they have not received my tax return for the year of 2018. I contacted them and they said that I should send it again with all required documents, they will look over it and let me know if any balances are due or if any documents are needed. I dont remember if I have sent it to them that year or if I forgot. Also, I think I didnt send them my 2019 tax return. And I think I fucked up big time. But anyways, I'll be sending them all the needed documents tomorrow. My question is, if any of u ladies had dealth with this, how much of a "fee" all together did u have to pay?