Still seeking help; my OAuth signature is invalid. Thank you in advance!

Hi! I am working with Jira Cloud and an external, non-Atlassian application. As an administrator on both applications, I am setting up a page on my external application for my authenticated users to view a generated list of released Jira issues and corresponding details. I have set up my Application Link in Jira. While working with OAuth I am now receiving oauth_problem=signature_invalid. I am posting to https://XXXXXX.atlassian.net/plugins/servlet/oauth/request-token. My oauth_callback, oauth_consumer_key, oauth_nonce, oauth_signature_method, and oauth_timestamp all seem to be fine. Any advice would be appreciated.

The documentation has a lot of mistakes about the OAuth integration.

Some issues that I encountered:

1 - I had to copy the private key from the .pem file, not from the .pcks8 file.

2 - I had to copy the whole content from the files for the public and private keys, including the first and last lines, that indicate where the key begins and ends.

3 - It seems that Jira API does not supporte the HmacSha1 signature method. I had to use RsaSha1.

So, after a lot of struggle, i finally managed to generate the request key and access key. But still have no clue how to use the access key to access a protected resource.