(Note: Do not copy-paste from unreliable third-party sites – type this directly or search "SketchUcation Slicer 5").
Locate the "Download" button. The file name will be something like tig_slicer5_v1.2.rbz . Slicer 5 Sketchup Plugin Free Download LINK
The original plugin was developed for SketchUp 2015–2018. The developer, TIG, discontinued active updates several years ago. However, a community-managed version exists called which works reliably up to SketchUp 2023. (Note: Do not copy-paste from unreliable third-party sites