I e filed with TurboTax last year. How do I obtain my AGI from last year so I can file for this year?

You need your 2022 AGI to efile 2023. The AGI is on 2022 1040 line 11. If you filed a Joint return you use the same AGI for each spouse.

How to find the AGI.
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947

If you didn't file 2022 or filed it later in the year or mailed it, then try entering 0 for the AGI. If that doesn't work you will have to print and mail your return.

Or request a transcript from the IRS
https://www.irs.gov/individuals/get-transcript

See this TurboTax support FAQ for finding last year's AGI - https://ttlc.intuit.com/turbotax-support/en-us/help-article/internal-revenue-service/find-last-year-agi/L0SiDtTNI_US_en_US?uid=lt21sx9t