How do I pay my household employee federal tax withholding reported in W3?

I had a household employee in 2024 which I paid around $5k to. Back in January, I use SSA's Business Services Online tool to fill out a W2 for my employee which gave me a W3 form as well. However, I have not actually paid the withheld tax and my portion of social security and Medicaid tax yet. How do I pay that? would that be part of my individual tax return?