How to define subscript and superscript for the axis labels on terminal

Dear Alex,
I am trying to give my own notations for axis labels for the thermoelectric plots. As for thermal conductivity and conductivity, I want to use k_l (l should be in subscript and in italic) and sigma (in symbol form).
amset ********* --thermal-conductivity-label ‘K_e (W/mK)’ **.jason.
The above command is not working.

Try using latex

amset ********* --thermal-conductivity-label '$k_l$ (W/mK)'

Thank you very much.