Esri does not provide a native desktop version of ArcGIS 10.8 (ArcMap)
If you have a valid license and want to move your workflow to Ubuntu, here is the most stable way to do it. Option A: Using a Virtual Machine (Recommended) descargar arcgis 10.8 gratis con crack ubuntu
Introduction
Install Virtualization Software: If you're using a virtual machine, install VirtualBox or VMware. Esri does not provide a native desktop version of ArcGIS 10