hi using Delimited Based Connector it cannot provision the access and update your file preset on SFTP server. In general this is the process that will happen for disconnected based applications. When request is raised and approved in ISC SailPoint can use ServiceNow Service Desk and create a ticket in SNOW to the application team
Then application team will take the action in the target and update your SFTP file.
If there is no ServiceNow Service Desk config then SailPoint will create a Manual WorkItem you can check them in UI by navigating to Admin > DashBoard > To Do Activity.
Here also you need to close the workitem and update the file manually and run the aggregation back to SailPoint.
Either way you have to manually update the file unless you have implemented some customization outside to update the file.