Adding panel labels in figures (A, B, C in the top left, etc)

[Al Goods]

Hi there,
I am having trouble finding instructions online regarding how to add a panel label in the top left corner of my figure. For a single figure (eg. Figure 1) I have two embedded panels (Panel A and Panel B) and would like to have A and B in the top left corner above each panel. I think these labels would go in the "graph region" part of the Stata graph. Any advice appreciated!
Al

[Nick Cox]

See https://journals.sagepub.com/doi/pdf...6867X211063413 which is focused on this question.