The stream or file "/opt/project/storage/logs/laravel-2020-12-29.log" could not be opened in append mode: failed to open stream: Permission denied code example

Example 1: could not be opened in append mode: failed to open stream: Permission denied

chmod -R 775 storage
chmod -R 775 bootstrap/cache

Example 2: 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