Warning: Undefined array key "contents" in /workspace/export.php on line 11

Fatal error: Uncaught TypeError: sizeof(): Argument #1 ($value) must be of type Countable|array, null given in /workspace/export.php:12
Stack trace:
#0 /workspace/index.php(11): include()
#1 {main}
  thrown in /workspace/export.php on line 12