Hi,
You can use Tex Markup defined in Label Properties to add superscripts and subscripts in MATLAB to include special characters in the text. To create subscript, you can use _{ } modifier.
Please refer to the following example code demonstrating the implementation discussed above:
% Example data
x = 0:0.1:10;
y = sin(x);
% Create a plot
figure;
plot(x, y);
% Add labels with subscripts
xlabel('x_{label}');
ylabel('y_{label}');
Kindly refer to following MathWorks documentation to know more about Tex Markup in Label Properties discussed above: https://www.mathworks.com/help/matlab/ref/matlab.ui.control.label-properties.html?searchHighlight=label%20subscript&s_tid=srchtitle_support_results_4_label%20subscript#:~:text=of%20HTML%20markup.-,TeX%20Markup,-Use%20TeX%20markup
I hope the solution provided above is helpful.