Include hyperlink in custom Log Message

You can add a link to the context, something like this:

apply_filters(
  'simple_history_log',
  'This is the link: {link}',
  [
    'link' => 'https://example.com',
  ]
);

But the link will not be clickable beacuse of security reasons you can not add any raw HTML to the logged entry. If you want to be able to add a clickable link you must create your own logger and also implement a getLogRowPlainTextOutput()-method, for example as used in the SimpleUserLogger.