Hi,
It is challenging to provide a precise answer without seeing your data and describing how you created the plot.
I assume you used the Stacked Bar in GraphBuillder with an Overlay column for each bar and then selected the Label by Value to display the data within each bar (see below and the attached mock data).

If you used a different method, try the simple approach I described. If you prefer using a different method, please send us a description of each step.
Best,
TS
Thierry R. Sornasse