401K contribution

I want to contribute the maximum amount to my self employed individual 401K plan. According to IRS publication 560, it appears I can contribute $22,500 plus $7500 catch-up (I am over 50). Also an additional employer contribution- not sure what this amount is.

My total compensation was $37,012 and my net income was $23,673.

I am trying to enter these amounts into TurboTax and it appears that the maximum amount allowed is $22,000 (not $22,500) and the catchup amount is not allowed. What am I doing wrong?