Did you use the IRS non-filer website to register for the stimulus and now are trying to e-file a 2019 tax return?
If so, see this TurboTax support FAQ for how to proceed - https://ttlc.intuit.com/community/tax-topics/help/stimulus-how-to-file-your-return-after-getting-reject-r0000-902-01/01/1602609