dan4ikk

Надо перед расположение писать .\\ (.\)

Исправный код:

import document
f = ".\\document\\Литература.docx"

@dp.callback_query_handler(lambda c: c.data)
async def send_file(query: types.callback_query):
  with open(".\\document\\Литература.docx", 'rb') as f:
    if query.data == 'button1':
      await query.message.answer_document(f)
  with open(".\\document\\Литература.docx",
      "rb") as f:
    if query.data == 'button2':
      await query.message.answer_document(f)
  with open(".\\document\\Литература.docx", "rb") as f:
    if query.data == 'button3':
      await query.message.answer_document(f)

если у вас линукс то замените \\ на /