Retirement tax questions

Thank you for taking the time to respond!

Yes, I have paid for my return, so I am able to view my "worksheet".  It looks a little different than your example - it looks like the Standard Deduction makes an appearance on it?  (I am using standard deduction).

But I am still not following the logic behind it.

I had a $1200 payment from Canada, which was net after 15% was withheld ($300).

My US overall tax rate is just over 10%.

But, including the $1500 in US income, and plugging it the $300 tax payment made in Canada, it gives me a measly $179 to use as credit for 2023 and the rest goes into Carryforward.  I would expect the whole $300 paid would be recognized as taxes paid.  Or am I thinking about it wrong?