Clipping study area boundary

Hello all;

Please, which module should I use to clip the map boundary in the attached file?

Thank you in advance

Nigeria_Palmer_Drought_Severity_Index.pdf (333.3 KB)

Consulting the manual shows us that there are two modules that do clipping

and, please, make an extra effort to ask questions that are comprehensible. For example, by reading your message I have no idea on what you want to do.