Find the book's from the URL. For example, in https://archive.org/details/militantislam00jans , the identifier is militantislam00jans .
Amazon Kindles do not natively support Adobe DRM EPUB or PDF files. To read a borrowed Archive.org book on a Kindle, you must download the file to a PC or Mac using Adobe Digital Editions first, and then read it on that computer. Direct sideloading of borrowed ACSM files to Kindle hardware will not work without third-party format stripping, which violates the archive's terms of service. how to fix download a borrowed book from archiveorg
If you wish to remove DRM protection from borrowed books for personal offline access, several tools are available. Find the book's from the URL