Twitter API 1.1 returns an Authentication Error (Error 32) when sending the INIT command to start the video upload process - twitter-oauth

Question

I am trying to upload a video to Twitter using the chunked upload endpoint. For this I post to the endpoint '**https://upload.twitter.com/1.1/media/upload.json**' the 'INIT' command. n posting to the Twitter server I get the error below
{"errors":[{"code":32,"message":"Could not authenticate you."}]}
At first I had a doubt regarding the Oauth signature generation function. But I can post a tweet and upload a .png image to the https://upload.twitter.com/1.1/media/upload.json using the Oauth signature generated by this Oauth signature generation function
I could also post the 'INIT' command initiate the chunked upload of a video successfully using TWURL
I have pasted below the actual request and response which was captured using Fiddler
Request
POST https://upload.twitter.com/1.1/media/upload.json HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: upload.twitter.com
Authorization: OAuth oauth_consumer_key="", oauth_nonce="MDAwMDAwMDAtMDAwMC0wMDAwLTAwMDAtMDAwMDAwMDAwMDAw", oauth_signature_method="HMAC-SHA1", oauth_signature="BtxgmRxA1bt5FI2Hu3qhhVIb5Eg%3D", oauth_timestamp="1607577817", oauth_token="****", oauth_version="1.0"
Content-Length: 357
Connection: Keep-Alive
command=INIT&media_category=tweetvideo&media_type=video%252Fmp4&oauth_consumer_key=******&oauth_nonce=MDAwMDAwMDAtMDAwMC0wMDAwLTAwMDAtMDAwMDAwMDAwMDAw&oauth_signature=BtxgmRxA1bt5FI2Hu3qhhVIb5Eg%3D&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1607577817&oauth_token=********&oauth_version=1.0
Response
HTTP/1.1 401 Authorization Required
cache-control: no-cache, no-store, max-age=0
content-length: 64
content-type: application/json; charset=utf-8
date: Thu, 10 Dec 2020 05:23:39 GMT
server: tsa_k
set-cookie: personalization_id="v1_jQ8zK7e0TgY2uCQKkiVOgA=="; Max-Age=63072000; Expires=Sat, 10 Dec 2022 05:23:39 GMT; Path=/; Domain=.twitter.com; Secure; SameSite=None
set-cookie: guest_id=v1%3A160757781933882195; Max-Age=63072000; Expires=Sat, 10 Dec 2022 05:23:39 GMT; Path=/; Domain=.twitter.com; Secure; SameSite=None
strict-transport-security: max-age=631138519
vary: Origin
x-connection-hash: 0e6ebd96e051b8f7a413fb79c51a8f42
x-frame-options: SAMEORIGIN
x-response-time: 182
x-tsa-request-body-time: 0
x-xss-protection: 1; mode=block
{"errors":[{"code":32,"message":"Could not authenticate you."}]}
i googled a lot for a solution to this issue but none of the solutions are working. I also read the relevant Twitter documentation many many times
Thanks in advance for any tips
Mathew

Answer 1

Finally found what was causing the error. While passing the URL to which data has to be posted to the function that I use to generate the Oauth signature I was passing 'https://upload.twitter.com/1.1//media/update.json.com' instead of 'https://upload.twitter.com/1.1/media/update.json.com'. One additional '/' character was the reason why the error was occurring.
Thanks and regards
Mathew