How to prevent the user from changing the server data on the settings of the kobo collect app?
You should create a data collection user account which will have limited access only data collection. That way you are able to have control of what the account sees.
So how to prevent him from edit the server settings?
You can definately set an admin password on the menu for admin settings tab
Tap the three dots and you will see them
Choose user settings
Deactivate what you would like them not to see
Remember you have to do this in each and every device.
PS. Remember to set an admin password