How to add a static constant line to a chart?

To add a constant line X, go to module ASPECT -> X Axis -> Advanced X Axis -> Constant Lines X,

To add a constant line Y, go to module ASPECT -> Y Axis -> Advanced Y Axis -> Constant Lines Y,

Add a static constant line, and configure it

e.g.

How to add a dynamic constant line to a chart?

You can also add a dynamic line base on a value, in this case, you need set 'Custom" as type of constant line.

1 : Add the values you need for constant line to measures.

2 : Go to ASPECT -> X Axis (or Y Axis, it depends the value to add) -> Advanced X Axis -> Constant Lines X

Here is the outcome.