Translation:Please show me the textbook.
You're right. This verb doesn't require an indirect object like 'me' or 'him' but by its very nature (because of its meaning) it will always have a spot for an indirect object. And while 'me' would more often than not be that indirect object...I feel that's not the case in this section. It could just as easily be 'show the class...' or 'show them...' duolingo should really specify the indirect object here. わたしにきょうかしょを見せてください クラスに教科書を見せてください Etc. If it marked you wrong please flag it and tell them the sentence is too ambiguous. Thanks!