If you run asp.net website and have feature to upload files or update database/text file, you need to enable asp.net write permission (or Network Service)
1. Login to DotNetPanel
2. Navigate to User > Hosting Space > File Manager > Specific Folder that needs write permission
3. Click on Lock icon to bring up File/Folder Permissions window
4. Check box Network Service Write
Your asp.net application should have write permission on the folder now.
Helm control panel does not support this feature and you will need to request technical support to enable permission required.