The advantage to show some important events in a chart is that I can see clearly the evolution of the situation before and after:

Originally, this is my chart:

I will add those events in it:

NOTE: the “ID” column is optional, I will explain later how to use it

In the “secondary y-axis”, I will add the date of my events table:

From now on, I will always refer to this “secondary y-axis”. I will deactivate its line and activate its marker so I make sure to select only this one in the “series” field:

NOTE: for the marker, I change the color to orange

I will create 2 measures for my events table like that:

In the “secondary y-axis”:

• Click on the “fx” of the minimum range to select the “measure”:
  
• For the maximum range, I put 4
  

NOTE: based on your data, you will have to change the minimum and maximum

I will activate the “data label” and in the “series” I make sure to select it then:

• In the “position” of “options”, select “above”:
  
• Deactivate the “value” and activate the “detail”:
  

In the “detail”, click on “add data” to select the events name:

I will activate the “error bars” inside the magnifying glass and in the “lower bound”, select the “measure 2”, again make sure to select only this one in the “series” field:

And to finish, I just need to personalize my visual. Remember about the optional ID column ? I use it if I have a lot of events because each event, instead to be at the same height, will be at different levels, avoiding that event names are mixing between them. To use it, I will create first a measure:

Then put it in the “secondary y-axis”:

Now, I just need to repeat the process above and that’s it: