At first, check the debug
folder on your project that there it is
Next:
var connectoinString=Path.Combine("Data source=", Environment.CurrentDirectory, "F4FDataSQLite_SingleTable.db")
// or
var connectoinString=Path.Combine("Data source=", Application.StartupPath, "F4FDataSQLite_SingleTable.db")
using var con = new SQLiteConnection(connectoinString);
con.Open();
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