If it was rejected, then it was not filed. You would have to fix whatever caused it to be rejected and resend, or you can print it and mail it. Just be sure to sign it and include W-2 form from employer and any other necessary forms when you mail it in. The IRS will use your tax return to determine your stimulus. See this website concerning that:
https://www.forbes.com/sites/anthonynitti/2020/03/26/when-you-file-your-2019-tax-return-will-impact-...
