sqlite3 to db conversion most likely represents data export between two database formats, in this particular case from SQLite 3 database (.sqlite3) to one of the many possible generic .db files. It's hard to give specific answer about such export, considering the many possibilities when it come to the output format. But generally speaking, any database tool that can work with Sqlite 3 databases should be up for this task.
Updated: November 6, 2023