You have opened a project. File > Extras > Command group Organize > Project > Command group Optimize > Compress project.
In this dialog you can specify a scheme for the scope of compression. The last settings used are saved for each project.
Overview of the main dialog elements:
In this field, you can select a scheme containing the desired compression settings. Click [...] to open the Settings: Compression dialog. Here you can edit existing schemes or create a new scheme.
See also