views – How to change the name of the result of the rest of the export?

I have a custom entity (ContractSubscription) created in a custom module (amap).
One of its fields (contract_id) is a link to another custom entity (Contract) of the same module.

I've created a view to export the content of ContractSubscription as a csv file with the help of REST export.
Among the parameters of the view, I have:

  • Path: / amap / contract / export
  • Contextual Filters: Contract Subscription: Contract & # 39; (This allows me to see only subscriptions related to a specific contract)

When I go to mysite / amap / contract / export / 2, I have the expected result that I can save locally:

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As far as I know, the result name is defined by the actual access path when running the view, that is, "2", which corresponds to the end of the access path (in fact, the value of the contextual filter).

I would like to have something like "Contract2.csv" instead of "2".
How can I do that?