I wanted to know if I built this right. Please let me know if I made any mistakes or ways I could have made it better!

Build a conceptual ERD using the below list of Business Rules.

Each sales representative writes many invoices and must write at least one invoice.

Each invoice must be written by one and only one sales representative.

Each sales representative is assigned to one and only one department.

Each department must have at least one sales representative but could have many.

Each customer may generate many invoices, but information is stored for customers who have not generated any invoices yet.

Each invoice is generated by one and only one customer.

Each invoice contains at least 1 invoice line item, but ideally many line items.

Each invoice line item belongs to a single invoice.