https://developer.twitter.com/en/docs/basics/authentication/guides/creating-a-signature.html
The link at the bottom regarding hash_hmac has slightly broken English and no href property.
… also on this page: https://developer.twitter.com/en/docs/basics/authentication/guides/creating-a-signature.html#
“The sample request includes a single parameter in both locations (shown in bold)” Nothing here is in bold.
@Eric_WVGG Thanks for the feedback! We’ve logged the issue and will fix the links in a future release.