You can only do 2023 in the Online version. For prior years you need to buy the Desktop program for each year. They only sell the last 3 years. You have to file each year separately.
How to prepare a prior year return
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-prepare-a-prior-year-tax-return/00/25...
To do a prior year return you have to buy the Desktop program here,
https://turbotax.intuit.com/personal-taxes/past-years-products
You will need a full Windows or Mac to install it on.
