Is it possible to make bulk insert via dynamic query (no stored procedure)?

Question

My question is simple like the title says. We are not allowed to create stored procedures. So I want to make this via dynamic query (non of any custom types creation, etc.).

It should be so simple as:

command.CommandText =
                        "INSERT INTO XXX.privileges VALUES (" +
                        ":in_role_type," +
                        ":in_who," +
                        ":in_action_type," +
                        ":in_privilege_type," +
                        ":in_object_type," +
                        ":in_keys)"

Where all parameters are scalar values, but in_keys is an array of integers.

I've tried this approach:

And the error is below:

Unable to cast object of type 'System.Int32' to type 'System.Array'