RCurl interacts with digital client certificate(.pfx)

[kokomoo]

I'm quite addictive to RCurl now.
Here is my request, try to download a zipped file

response = getURL(url ="https://misapi.ercot.com/misdownload/servlets/mirDownload?doclookupId=598807743")

I'm working on Windows OS.
This request would work if I imported the personal certificate (some pfx/p12 file) into the browser.
If i removed it, it would have the error.

schannel: failed to receive handshake, SSL/TLS connection failed.

My goal is to run it independently from OS.
I have tried bringing in config list with params cainfo, sslcert, sslkey, somehow it's still showing the
same error.

My question is, what on earth happened once I imported a pfx into the browser and how does RCurl/curl know which one to use? I mean if I put the url in the browser, the prompt always shows the right collection to choose from.

Thank you