Every card by bureau will surely be answered by bureau.
Your card will be forwarded by the QSL bureau of the DARC e.V.
Send your reception report or QSL card and 1 IRC to
Daniel Moeller, Kolonnenstrasse 20, 10829 Berlin/Germany.
Each QSO will be uploaded on LOTW. As this is not an automatic routine please be patient. I do this like twice a month.
eQSL is not my preferred QSL as I like papercards and matches on LOTW. But if everything fails this is also an option.