USexpat22

I am a US-person working and living in the UK, so both countries have the right to tax my worldwide income. I had some consulting income from the US in the tax year 2022-2023. I am confused about how much foreign tax was paid on my consulting income on the Self Assessment form. My US tax calculation shows that I owed roughly 20% of it to the US, but I was able to use tax credits (such as child tax credits and foreign tax credits that the US allows) to essentially cancel out all I owed. I am confused what to enter on my self-assessment: should I enter the 20% value I calculated or should I enter 0?