I filed taxes with TT earlier this year and recd my refund. However, I missed deadline to open IRA for 2023, which I agreed to do in order to lower AGI. What are options?

You must amend your tax return to remove the IRA contribution and the deduction.

Did you enter on the 2023 tax return that you filed the amount of Traditional IRA contribution you were making on or before April 15, 2024?  If you did and then did not make that contribution, then you will need to amend the 2023 return and remove the IRA contribution.

See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-already-filed/L4VjJ9BA2_US_en_US?uid=ld1n99kr