In '22 I took the standard home office depreciation. For '23, I'm taking the itemized deduction, however, it is asking for last years depreciation amt which don't have?

See this link on the IRS site on how to calculate this. Although you don't have to use the same method each year it is generally better too because of the need to calculate this amount.

whether you take itemized deductions or the standard deduction this has not to do with the home office deduction (HOD). Generelly, the HOD is not available to employees.  Otherwise, one year you can use the simplified method and next year to the actual expense method (AEM) with the AEM you'll need to keep track of the depreciation you take because that is subject to recapture on the sale of the property. TurboTax will not track this if you change methods. 

Leave it blank (blank, not zero).