Running into problems with my first strategy

[catorRunner]

First, I am know close to nothing about JS (I am taking a online course at the moment) 
The simple strategy I am attempting to create uses Tulip HMA and WMA (and I 'll add some other stuff later) 

I used the "moon" strategy (from the intro video) as my base to and I am attempting to add WMA to it but for some reason, parameter for WMA I set in .toml file is not read. 

Code:

strat.init = function() {
...
     this.addTulipIndicator('wmaS', 'wma', {
      optInTimePeriod: this.settings.wmaS
    });

and in my toml file, I got  wmaS = 21

The error I receive is: 

Error: Gekko was unable to configure Tulip Indicators:
       optInTimePeriod needs to be a number

What am I missing?