It seems like you're not currently logged in to eRestavracija, so this form has been presented to you. You have a different username and password combination used for applying and opting out from menus. In order to use this feature, you have to log in with your Lopolis account.
Usage:
Click on a date to open the collapsible menu with choices and click on a specific meal to select it. Reload the meals when you're done and check the entries.
Note:
App was not tested with lunches in mind. Meals probably won't work with lunches and having a lunch subscription may even break its functionality.
Note:
If a meal is not present in the Meals collapsible field, this does not necessarily mean it does not exist. Meals that haven't been altered by you or are unchangable
(read-only) are not shown for clarity.
Note:
You are welcome to contribute to the LopolisAPI project source (py) and add features, such as checkouts.