@subins2000 It seems debian is missing sqlite's fts5 extension which is required by varnam:
$ ./varnamcli -s ml varnam
2023/02/03 18:06:57 no such module: FTS5
Do you plan to have varnam included in Debian ? Maybe @praveen can help? It looks enabled here
https://sources.debian.org/src/sqlite3/3.40.1-1/debian/rules/?hl=73#L73
$ sqlite3 test.db
...
sqlite> CREATE VIRTUAL TABLE email USING fts5(sender, title, body);
sqlite> .tables
email email_content email_docsize
email_config email_data email_idx
works too.