Hi!
1. https://earthexplorer.usgs.gov/
2. Create account , it is free and then logging to USGS
3. Select your Area of Study
4. Select Data Sets (Shown below)
5. Select Digital Elevation
6. Select SRTM
7. Click the Result tap it appear both in the top and bottom.
8. Make sure the DEM cover your area of sutdy
9. Select DEM match your area of study, before start download.
10.
11. Then merge your DEM and enjoy working with ArcGIS Pro and AOLN.
Good luck.
Faiez
GIN