Where do I enter the SEP IRA contribution. It's not listed under Deductions & Credits-retirement?

What version do you have?  

Go to Search and try entering "self-employed retirement" to get the Jump To link

Go to Federal
Income and Expenses and then scrolling down to the Other Business Situations section.
Click Start or Update beside Self-Employed Retirement Plans.

For Desktop
Click Federal Taxes > Wages & Income > I'll choose what I work on.
On the "Your 2024 Income Summary" page, scroll down to the Business Items section. Click the Start or Update button for Business Deductions and Credits.
On the Business Deductions and Credits screen, click the Start or Update button for Self-employed retirement plans.

Home & Business version
Go to Business tab - Continue
I'll Choose what I work on
Scroll down to Less Common Business Situations
Self Employed Retirement - Start or Update