@lindemananthony if your state payments were through withholding you can request duplicate w-2s from your employer or for a fee get complete copies from the Social Security adm. the IRS does not get state withholding data
https://faq.ssa.gov/en-us/Topic/article/KA-02501
if you made payments through a bank you can get copies of the statements to identify the payments and then get copies of the checks front and back. Even if you paid directly through the state's website there is identifying info on the bank statement which should allow the state to track down the payment.
if paid through a credit card there should be identifying info on the statements so you can request supporting info.
