I have been already working in stata for a while for my thesis, but now I realized that the results would be better if I add some more control variables.
I added two more coumns in my Control Variables dataset in excel but the new columns dont appear in STATA as new variables.
What can I do that STATA can import the modified excel? I tried to re run the command I used to import it for the first time but still does not work:

* add other control variables
use "$dir2\Control Variables Annual", clear
rename code reporteriso3
merge 1:m reporteriso3 year using "$dir1\WITS_Dispute"
drop _m
save "$dir1\WITS_Dispute_with_controls", replace

Any idea of how can I make stata identify the changes in the dataset?

Thank you very much and have a nice weekend!