Was it prepared with Online TurboTax?
If so, what is the roadblock? Do you not find it in that account? Or do you find it OK, but when you click to download, is there some kind of problem?
Log in and look in the section "Your Tax Returns & Documents", expand that section, and choose tax year 2018. Then look for a link "Download/print the PDF." If it's not in that account, then you likely have multiple accounts, and we can tell you how to find the right one.
I cannot see my returns in the documents. I think I may have multiple accounts.
You have to sign onto your online account using the exact same user ID you used to create the online account.
Close all TurboTax windows on your web browser (including this one). Copy and paste the account recovery website link onto a new web browser window and run the tool.
Use this TurboTax account recovery website to get a list of all the user ID's for an email address. Run the tool against any email addresses you may have used - https://myturbotax.intuit.com/account-recovery
If none of the user ID's received will access your account, then use the option shown in blue on the account recovery website, "Try something else"
If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created. TurboTax does not store online any returns completed using the desktop editions.
To access your prior year tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/