American Expats in Germany filing tax question

We are US citizens who spent part of 2019 in Germany. Husband worked in Germany, I didn’t. We are waiting to hear back from Germany on if we get a tax refund from Germany. And we are ready to file our US taxes, listing the 2019 German payroll taxes, not including any possible German tax refund. Do we need to wait until we hear from Germany on if we get a tax refund before filing our US taxes so we can reduce the amount of German payroll taxes on our US filing if we get a German refund?

Thank you.

Assuming you are a tax basis taxpayer, as are almost all individuals, you report these events as the transactions occur. So you report all your withholding for 2019 with your 2019 US tax return. In 2020, if you get a tax refund from Germany, you report that on your 2020 return.