Here you can find how to create a quote.
Navigate to QUOTES>Spot Quotes
Click on "Create quote".
Complete the necessary details (similar to when you create an order).
Once created, you can send the quote from Qargo directly to your customer. In order to do this, you would first create a task in configuration to:
Generate a quote
Send the quote.
To generate the quote, you would need to create a template as explained here.