METS/MODS export from Darmstadt Repository not working

[igorbajena]

I received a sample of METS/MODS file from Darmstadt. I try to test it with the DFG 3D-Viewer by putting the link withtin DFG 3D-Viewer URL, but it didn't work:

METS/MODS by Darmstadt: https://ingest.nfdi4ing.de/api/v1/oai-pmh?verb=ListRecords&metadataPrefix=mets

Test with DFG 3D-Viewer: https://3dtest.dfg-viewer.de/viewer?tx_dlf[id]=https://ingest.nfdi4ing.de/api/v1/oai-pmh?verb=ListRecords&metadataPrefix=mets&no_cache=1  
  
Can you look at it, what is wrong? It could be that the reason is that link is not finished with ".xml" extension?