Upload external notes

<b>Deprecated.</b> Use POST /api/v4/f/{firm_id}/companies/{company_id}/client_meetings/attachments instead, which supports attaching multiple files to a meeting.<br><br> Upload an external note to the current client meeting for the specified company.<br><br> Supported file types: .aac .flac .mp3 .mpa .mpeg .mpga .mp4 .opus .pcm .wav .webm .png .jpg .jpeg .webp .txt .pdf<br> <b>Required scope:</b> client_meetings:external_notes:write