Set some non-existent parameters in multipart request

Questions
1

OB2

POST /v2/online_check.php HTTP/1.1
Host: api.sites.com
Connection: Close
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.6422.60 Safari/537.36
Accept: application/json, text/plain, */*
Origin: https://sites.com
Sec-Fetch-Site: same-site
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: https://sites.com/
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Content-Type: multipart/form-data; boundary=------WebKitFormBoundaryhtifklemrdlljtab
Content-Length: 214

--------WebKitFormBoundaryhtifklemrdlljtab
Content-Type: text/plain; charset=utf-8
Content-Disposition: form-data; name="ip_addr[]"

0.0.0.0:1234-0
--------WebKitFormBoundaryhtifklemrdlljtab--

Browser request

POST /v2/online_check.php HTTP/1.1
Host: api.sites.com
Content-Length: 154
Accept: application/json, text/plain, */*
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary5kTzLkfBhC63ZeOb
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.6422.60 Safari/537.36
Origin: https://sites.com
Sec-Fetch-Site: same-site
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: https://sites.com/
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Priority: u=1, i
Connection: keep-alive

------WebKitFormBoundary5kTzLkfBhC63ZeOb
Content-Disposition: form-data; name="ip_addr[]"

0.0.0.0:1234-0
------WebKitFormBoundary5kTzLkfBhC63ZeOb--

I don’t understand why it has to be set to this parameter Content-Type: text/plain; charset=utf-8 when it does not exist in the original request

2

It’s a limitation of the current multipart requests system in OB2. You can either build your string manually via a standard http request or wait for a rework.