you would need to do a re-characterization from Roth to Traditional (including any earnings in the Roth from this contribution) and you would enter that in your 2025 taxes in the IRA section but enter it as Roth contribution and answer the questions about the re-characterization (see guide below).
assuming you are classifying the Trad IRA contribution as non-deductible it should reflect on Form 8606 Line 1 in your return with basis carried over to 2026 on Line 14 (the subsequent Roth conversion part is a 2026 tax event - see below).
next year you'll get a 1099-R with code "R" for the re-characterization which doesn't do anything in your return as you already put it in for 2025.
you can then do the Roth conversion part of the backdoor process for the full amount (7000 + earnings) after the re-characterization but Roth conversions are applied in the calendar year they do not back-date to prior tax year, so you would get a 1099-R for the conversion this time next year and report in 2026 taxes. Assuming the Trad IRA contribution was non-deductible and you have no other IRA balances other than the re-characterization, conversion of the $7000 basis would not be taxable in 2026 but any earnings above that from this whole process will be taxed. (If you do have other Trad IRA balances (not Roth or 401k) then the conversion is considered taken from both pre-tax balance and after-tax basis across all your IRAs, and your conversion taxed accordingly).
not a CPA but that's my understanding, hope that helps, see also:
https://ttlc.intuit.com/turbotax-support/en-us/help-article/retirement-income/recharacterize-roth-ir...
https://ttlc.intuit.com/turbotax-support/en-us/help-article/retirement-benefits/difference-conversio...
https://ttlc.intuit.com/turbotax-support/en-us/help-article/retirement-benefits/enter-backdoor-roth-...
