Who should the self-employment receipt be issued to, and for what amount?

On standard Upwork contracts the service agreement is between you and the client, with Upwork holding and passing on the payment. The receipt is therefore issued in the name of the client abroad named in the contract, for the gross amount the client paid. The fee Upwork deducts is a separate charge for Upwork's own service and is recorded separately against Upwork's invoice.