I've separated from my (marital)partner, but I'm still being asked for their net income. Which I don't know.. and it won't allow me tp put in a value of 0.00?

When you select the married filing separately (MFS) filing status then you should not be asked about income for your spouse. Unless you have a legal separation or you qualify for Head of Household (HOH) filing status this would be you only filing status option. This would require a child dependent that lives with you and the separation occurred before July 1st.  

• Do I qualify for Head of Household in 2024?

Based on your question the answer assumes you were married. Please update here if you have additional questions and we will help.

Is this in your state return?  Can you provide more context?  Generally, your spouse's income is not relevant if you file married filing separately, but it might be required for certain state credits, or maybe for the kiddie tax or for medical insurance subsidies.  In these situations it is sometimes allowed to estimate, and if you later find out the estimate was wrong, you may need to file an amended return.  But we need to know more about why you are being asked.