Inno Setup cannot create a zip file for you while compiling.

But you have two options how to delegate the zip creation to an external process

1. If you are automating complex build process, you will likely be running Inno Setup command-line iscc compiler. So just before running it in your batch build process, run another process/software/tool to create the zip file.

   For some example, see:

   • Inno Setup Pre- / Post- compile action

2. If you really want to create the zip file on the fly, while manually building the installer in Inno Setup GUI, you can use preprocessor Exec function to start an process/software/tool to create the zip file before the actual compiling begins.

   For some examples, see:

   • Inno Setup Pre- / Post- compile action
   • Create files in Inno Setup setup needed by the [Files] section
   • Is it possible to call a batch file while compiling an Inno Setup script?

As for the actual zip file creation, that's not really Inno Setup question anymore. You will file lot of question about that, for example:
Batch file script to zip files

Inno Setup cannot create a zip file for you while compiling.

But you have two options how to delegate the zip creation to an external process

1. If you are automating complex build process, you will likely be running Inno Setup command-line iscc compiler. So just before running it in your batch build process, run another process/software/tool to create the zip file.

   For some example, see:

   • Inno Setup Pre- / Post- compile action

2. If you really want to create the zip file on the fly, while manually building the installer in Inno Setup GUI, you can use preprocessor Exec function to start an process/software/tool to create the zip file before the actual compiling begins.

   For some examples, see:

   • Inno Setup Pre- / Post- compile action
   • Create files in Inno Setup setup needed by the [Files] section
   • Is it possible to call a batch file while compiling an Inno Setup script?

As for the actual zip file creation, that's not really Inno Setup question anymore. You will file lot of question about that, for example:
Batch file script to zip files