You must enter the Roth IRA contribution. Because it is an excess contribution, your tax return must include either an excess contribution penalty or report the return of the excess contribution. If your tax return includes neither, expect a notice of tax deficiency from the IRS.
The MAGI limits for a Roth IRA contribution are extremely low when filing MFS. It's extremely unlikely that filing MFS will be beneficial unless there is some other special reason to do so.
