You can review the Capabilities metadata document to discover if an action supports asynchronous requests.
https://sam.spclouddave.com/SampleService/Sppid/V2/Capabilities/$metadata
<Annotations Target="Com.Ingr.Core.V1.ExecuteReport (Com.Ingr.Core.V1.Report, Edm.String)">
<Annotation Term="Com.Ingr.Vocabularies.Core.V1.AsynchronousRequestsSupported" Bool="true"/>
</Annotations>
As shown, the ExecuteReport action does support asynchronous requests. See Notes on asynchronous execution flow for details on calling the action asynchronously.