How to pass HTTP headers in a Connection String

using command line., cmd batch file, powershell or what?

try this format

rclone ls -vv :http: --http-headers="Content-Type,application/json,Authorization,'1//0h9C5MPJwUJo4CgYIARAAGBESNwF-L9Ir4NoazoXYt8B1fHhAegRcmjISmndFatlUt_SYstasLG_zDjILrRxoeql4UKhWSsaR02k'" --http-url="https://downloads.rclone.org":/v1.62.2 
DEBUG : Setting --config "C:\\data\\rclone\\rclone.conf" from environment variable RCLONE_CONFIG="C:\\data\\rclone\\rclone.conf"
DEBUG : rclone: Version "v1.62.2" starting with parameters ["C:\\data\\rclone\\rclone.exe" "ls" "-vv" ":http:" "--http-headers=Content-Type,application/json,Authorization,'1//0h9C5MPJwUJo4CgYIARAAGBESNwF-L9Ir4NoazoXYt8B1fHhAegRcmjISmndFatlUt_SYstasLG_zDjILrRxoeql4UKhWSsaR02k'" "--http-url=https://downloads.rclone.org:/v1.62.2"]
DEBUG : Creating backend with remote ":http:"
DEBUG : Using config file from "C:\\data\\rclone\\rclone.conf"
DEBUG : :http: detected overridden config - adding "{mFj--}" suffix to name
DEBUG : Root: https://downloads.rclone.org:/v1.62.2/
DEBUG : fs cache: renaming cache item ":http:" to be canonical ":http{mFj--}:"
     3228 MD5SUMS
     3596 SHA1SUMS
     4700 SHA256SUMS
 16738480 rclone-v1.62.2-freebsd-386.zip
<SNIP>
 16127843 rclone-v1.62.2.tar.gz
       15 version.txt

else down the rabbit hole
https://forum.rclone.org/t/unable-to-use-on-fly-backend-with-configuration-string-in-shell/26625