script (opentype Feature)

[raghugada]

Hi,
I am trying to substitute glyps using open type feature

using the script
…
feature start{
lookup test;
}
lookup test{
sub j k → l;
}

after successfuly executing the script i see its not showing substitution

[ErwinDenissen]

Make sure the feature is added to the corresponding Script-Language.

script latn {
  feature start;
}

feature start liga {
  lookup test;
}

lookup test {
  sub j k -> l;
}

Also ensure you have enabled the specific feature: