If you made a direct Roth IRA contribution then this won't be reported on Form 8606. You Roth basis can be found on the IRA Information Worksheet.
Form 8606 part III is used if you took a nonqualified distribution form your Roth IRA.
Form 8606 is also used if you are using the backdoor Roth method to make contributions to the Roth IRA by making nondeductible traditional IRA contribution and converting them to Roth IRA.
Please see Who Must File 2024 Form 8606 for additional information.