Embrace the alternatives.
These are modified installers created by unknown third-party groups. They take the original Office 2019 files, attempt to virtualize the registry calls, and bundle them into a single executable. Examples include repacks from groups like WZT or Ratiborus (though these are often for activation, not true portability).
How to activate and install Medialess Office 2019 or Office 365
Portable Office usually supports loading add-in files manually: