options
non-simple requests found on the Internet must meet the following conditions:
request method is one of the following three methods:
HEADGETPOST
The header information of HTTP does not exceed the following fields:
AcceptAccept-LanguageContent-LanguageLast-Event-IDContent-Type:application/x-www-form-urlencodedmultipart/form-datatext/plain
HeaderServerOption
I have all set json format here, why the first one didn"t send options pre-check