Configuration with Cockpit config.php file

[Flaminiat]

Hello,
I am trying to add Detektivo-Algolia to my Cockpit but I cannot understand what I do wrong in the config.php file. All examples I found are with config.yaml but in my version of Cockpit the config file is .php.
I tried by going to Settings --> settings --> config/config.php and adding this:
'detektivo' => [
'engine' => 'algolia',
'app_id' => 'MXXXXXI',
'api_key' => 'xxxxxxxxxxxxxxxx'
]

but once saved I get this error:
Parse error: syntax error, unexpected '"detektivo"' (T_CONSTANT_ENCAPSED_STRING), expecting ']' in /var/www/html/config/config.php on line 6

What I am doing wrong?
Thanks