Output modifier on placeholder

[vierkantemeter]

Hi there, thanks for this addon!

I'm having some difficulty with an output modifier on a placeholder from a get param. Am I doing something wrong, or is this not possible?

[[!setPlaceholders? &ph=success==get.updpsuccess]] [[+success]] [[+success:eq=1:then=Success!:else=Fail!]]

Thanks for your help, Michèlle