Error while creating an RFQ

Hello Everybody,
I am performing a Request for Quotation procedure.
The Steps which I am performing is as follows.
Step 1:

I had created a new Request for Quotation where at the Line level I had Select a (Non Catalogue Item /line type= Category) followed by Procurement Category and Providing (Description/product name as “Desktop”).
Note: I had not entered any Quantity and Unit Price
Step 2:

I had selected my Vendor from which I need the Quotation Price.
Step 3:

I had clicked on the check Box at the line level.
Now when I am clicking on “Send button"

A new window is popped out where I am not able to see any item at line level which I had selected in the RFQ Document and moreover at the header level I can see a yellow triangle which Showing an Error.
Please suggest that am I missing any configuration?

How can a vendor give you the quotation without telling the quantity?

I don’t think you can process RFQ without specifying quantity in the RFQ lines.