Dear Joan,
I checked up in SNAP, actually the problem as you see SRTM 1sec and 3 sec , both they don’t cover the AOI,
However, GETASSE30 covers the AOI,
Coming back to python script, you have two options, the first one is to use GETASSE30, Or/And to download other tile of DEM, covers your AOI, and you could check up the projection in SNAP using this icon,
the highlighted one,
It’s simple to reproject in SNAP from Raster—>Geometric Operation—>Reproject
Also the error, you posted, refers to other
I don’t think this is related to DEM, while you used GETASSE30, but might be it should be in upper case DEM = ‘GETASSE30(Auto Download)’ , without indentation between 30 and the bracket,
Take a look at similar problem in this thread, Source of the thread
Please let me know if it helps,