Recover libreoffoce file in lubuntu

I have lubuntu and I write document with libreoffice (6.3.2.2) during the last 2 weeks, the file size was around 100-130 kb.

During this time I saves this document and shutdown my pc few time.

Today when I tried to open this document I saw the file size is 9 kb, and I got error Some errors were encountered during the import.

How can I recover my document?

Some errors were encountered during the import.

Does this mean that you are not using ODF file format (.odt extension) but some other format (maybe .docx)?

I use odt extension