Hello,
Is it possible to trigger the scheduled task after a new user is created?
Yes, you can run a PowerShell script that will execute the scheduled task in a business rule triggering After creating a user. For an example of the script that executes a scheduled task, have a look at the following SDK article: https://www.adaxes.com/sdk/SampleScripts.ExecutingScheduledTasks.
Or is there another solution to save a report in the filesystem after user creation?
If you use the Run a program or PowerShell script action in a scheduled task to generate and save the required information, then you can consider creating a custom command that executes the script. Then you can run the command in the business rule triggering After creating a user and in a scheduled task. If this is not how the reports are generated, please, provide us with all the possible details regarding the workflow you currently have. Screenshots and live examples will be much appreciated. You can post them here or send us at support@adaxes.com.