SSRS Subscription is a tool that allows you to run an SSRS Subscription manually, to see to running jobs and the executions logs.

Important : Before running SSRS Subscription Tool, make sure to update the SSRSConnections.xml file, by setting the servers names where your SSRS reports and subscriptions are deployed in a XML format (You can put many connections):

<SSRSConnection>
    <ServerSQL>The server name of the database engine reporting server</ServerSQL>
    <Database>The name of SSRS database, generally It's "ReportServer"</Database>
    <PrefixURL>URL of the reporting server</PrefixURL>
</SSRSConnection>