Forign Trade

1. Cannot be Export , as goods never delivered beyond custom Frontier. as per Definition of export of goods u/s 2(5) IGST act , taking goods out of India. So it deemed to be domestic transactions.
2. Yes its an supply under Section 7, hence GST attracts.
3. you need to issue only one invoice as per the provsion of section 31 of CGST Act

One Invoice means Indian Invoice  , if we create Invoice in Indian Rupees then Outside India party how to show this in account because we received from party USD.

AS PER GST LAW YOU ARE REQUIRED TO SHOW TAX INVOICE IN INDIAN RUPEES . YES YOU CAN MENTION THE US$ THEREIN

Which party name mention in INVOICE  Bill To...... and Ship To.....