There are many platforms to download DEM and other topography data. One platform that I found very useful is open topography. There are huge varieties of topography dataset such as high resolution topography data, point cloud data, global and regional DEM and community contributed data.

To download any of these data, go to https://opentopography.org/. Click FIND DATA MAP under the DATA menu. This directs to a map where the region of interest can be selected and available data are listed. Select the data you want to download and submit the job. The data will be ready after some minutes.