Translation of Theme with “Loco-Translate”

Hi There again, I tried to translate some english words (e.g. Prev Post ... Next Post) into German Language (Vorheriger Beitrag ... Nächster Beitrag) and normally i use the Plug-in "Loco Translate". But it seems that the Loco-Translate Plug-In is not compatible with the Theme. The advise from Loco-Translate was to inform the Creator of the theme. Is there another way, to translate some words into another language or substitue the text ? BR Dirk