Most people have used options with Dial. e.g. this example from the Dial() documentation, which has two options (B and b), both with parameters:
Dial(PJSIP/alice,,b(default^called_channel^1(my_gosub_arg1^my_gosub_arg2))B(default^callee_channel^1(my_gosub_arg1^my_gosub_arg2)))
Of course, like with Dial, you need placeholders for the missing parameters, and you are missing those.