UnexpectedValueException : The stream or file could not be opened in append mode: failed to open stream: Permission denied code example

Example: could not be opened in append mode failed to open stream permission denied

Reference link if giving a permission doesn't solved your issue
https://www.digitalocean.com/community/questions/the-stream-or-file-var-www-html-myscipt-storage-logs-laravel-log-could-not-be-opened-failed-to-open-stream-permission-denied