You cannot install the application on a USB stick and run it on a stranger's Mac (macOS prevents this due to security certificates). However, you make your working environment portable.
Here is the truth about Lightroom and macOS portability. Yes, but not the way you think. lightroom portable mac
| Solution | Best for... | Portability | Price | | :--- | :--- | :--- | :--- | | | Speed demons | Native on Mac; works great off external drives | $49.99 (One-time) | | Darktable | The Frugal Pro | Open source; runs fast on Intel/Apple Silicon | Free | | Adobe Lightroom (CC) | Cloud lovers | 1GB app; all photos stored in cloud (not local) | $9.99/mo | The Verdict Don't search for "Lightroom Portable Mac" anymore. It is a myth. You cannot install the application on a USB