Adding "levels" to "SlopeDirectionLine" indicator

[Gerhardt76]

Hello. Can someone help me to add a levels tab to the SlopeDirectionLine indicator. I want to build a channel around it.

I noticed that the standard moving avarages indicators, not the custom one, has this function.

I have tried adding the following, but nothing...

#property indicator_level1 50
#property indicator_level2 -50
#property indicator_levelcolor LimeGreen
#property indicator_levelwidth 1
#property indicator_levelstyle 1