How to add activities to redmine timesheet plugin?

I am using redmine, a great project management web application, and added littestream timesheet plugin.
If you want to add timesheet activities, you can't do it from the UI. You need to add it directly into mysql db like that:

insert into enumerations values (10,'Experimental Development', 3, 0, "TimeEntryActivity", 1, NULL, NULL)
insert into enumerations values (11,'Scientific Research', 4, 0, "TimeEntryActivity", 1, NULL, NULL)

Don't forget to set property the id and the position.

select * from enumerations;

| id | name | position | is_default | type| active | project_id | parent_id |