First, make sure the 2018 state return was successfully filed.
If you used Online TurboTax, log in to your account and at the Tax Home scroll down to "Your Tax Returns & Documents." Expand that section and choose tax year 2018. What is showing for the state return--does it say accepted, rejected, printed, started, ready to mail, or what?
If it was successfully filed, here's how to contact the state tax agency to check on it:
https://ttlc.intuit.com/community/state-taxes/help/how-do-i-contact-my-state-department-of-revenue/01/25573