The different parameters you can set up on this site are:
Automatically assign members this role: Select the role that you want to bot to auto assign (only one role can be auto assigned).
Minutes of membership required for role: Requires that a member must be on the server for
x minutes before assigning the role.
Require one of these roles to be present on the member: If a person does not have one of the following roles on them they will not be given a role.
Ignore people with the following roles: If a person has one of the following roles on them they will not be given a role.
Only assign role when they join, do not give it back if it's removed from them afterwards: Only assign the role to them once when they joined. If they lose the role sometime after, the bot will not give it back to them. Note that this means what it says - if this option is unticked and you remove this role manually from someone, it will be given back automatically.