Form 5498 is not filled out as part of your individual tax return.
It is completed and sent to you by the financial institution that is the custodian of your IRA account. After you have made a contribution to an IRA, the financial institution will generate Form 5498 for you and the IRS to show the amount of your contribution for the year and the total value of the account as of the end of the year. You will receive it mid-year and simply keep it with your tax records.
Sometimes this information is needed in order to determine the taxable portion of a distribution from your IRA, but you only need to report this as part of your tax return if you are asked to enter that information.
See the following TurboTax help article for more information: