Here are the simple steps to provide Read/Write permissions for any folder:
STEP-1
1- Click on your hosting plan
2- Click on customer security settings
3- Click on save
STEP-2
1- Click on websites
2- Click on website name
3- Check mark on enable write permission.
4- Click on update button.
STEP-3
1- Click on file manager
2- Click on website name
3- Click on wwwroot folder
4- Select the folder with the help of check mark
5- Click on lock icon
6- Check mark on Read/Write and Replace permissions on all child objects
7- Click on set permissions