Exemption is a tax credit that does not require filling out a f1116. The limit is $300 single and $600 married filing jointly. 11b is the total tax you owe after calculating income, deductions etc.
To elect to not use the exemption, here is the following technique.
Go to the Foreign Tax Credit Interview
The 1st screen header is "Foreign Tax Credit." Click Continue
The 2nd screen header is "Tell us about your foreign taxes." Check the box marked "none of these apply." This is necessary to avoid TT exiting the interview prematurely.
Continue with the remainder of the interview.
After TT exits the interview, in Forms Mode, in the left pane, click on the "Info Wks." Scroll down to Part VI; then to the 5th paragraph to the intro "Foreign Tax Credit (Form 1116)." Check the box and this will force TT to generate the f1116.
Then go to the f1116 wks.; scroll down to the carryover section, and you should see the credit is carried over to TY2019