Two tricks:
(1) When identifiers are not found then it is usually a situation like this:
Chart1.AxisList[2].Alignment := calRight;
Ctrl-click on "Alignment" and Lazarus will open the unit in which Alignment is defined, in this case TAChartAxis:
property Alignment default calLeft;
calLeft is another element of the enumeration you are looking for. So, Ctrl-Click on it again and Lazarus will open the unit in which calLeft is declared along with calRight - it is TAChartAxisUtils. (If you want to learn about the inner structure of some library this is way to go. Knowing how to navigate through the source code is superior to reading documentation (which is always outdated anyway).)
The disadvantage is that this method does not work if the unit with the identifier on which you do the first click is not in "uses". This is when you need the second trick.
(2) Install the package Cody. Trying to compile the program will fail because the identifier calRight is not found. In the message window there is a message "Identifier not found". Right-click on this message and select "Search identifier". After a short time, the IDE will tell you that it is in unit TAChartAxisUtils.