You can access the official ArcGIS Pro 3.1 installer and its subsequent cumulative patches through the following authenticated Esri platforms:
: Individual users with assigned licenses can download the software directly by signing into their organization, navigating to My Settings , and selecting the Licenses tab. esri arcgis pro 301 link
ArcGIS Pro 3.1 is a major update to Esri’s flagship desktop GIS software, introducing significant enhancements like catalog datasets, automated layout resizing, and the ArcGIS Reality extension. Official Download Links for ArcGIS Pro 3.1 You can access the official ArcGIS Pro 3