If you cannot find 10.8.2 in your My Esri portal, it may be hidden by default. You can:
Downloading ArcGIS Desktop 10.8.2 is a straightforward process for authorized users via the My Esri portal. However, organizations should treat this installation as a stopgap measure for legacy data management. The software is stable and robust, but the retirement of the product line necessitates a strategic plan for migration to ArcGIS Pro to ensure long-term security and support. arcgis desktop 10.8.2 download
Follow the prompts in the ArcGIS Desktop Setup wizard . You can choose between "Complete" or "Custom" installation types. If you cannot find 10