sorry if you dont understand embassies and their regulations - but i am happy you understand this issue here - just didnt see any advice for the OP how she can solve her problem...
maybe you misunderstood - i just gave you the embassy view - if you want to stay and not a an embassy letter - you havs these options - ED or Volunteer visas - via agency - pricey - or a medical certificate for
why EU should do letters - flights are going home - no Covid19 extreme situation - only way ED, Volunteeer Visa - or a medical certificate for 30-90 days -