How to implode array of value in PHP [closed]

I am trying to use implode in PHP to insert this array of values as below:

[13:00, 14:00, 15:00, 16:00, 17:00, 18:00] but for some reason I get an error message warning: implode(): Invalid arguments passed I implemented my implode as below:

$time_picked = [13:00, 14:00, 15:00, 16:00, 17:00, 18:00];

$time_slot = implode(",", time_picked);

Can anyone help out with this? I think I need to wrap each array after the comma with a " " but will be glad about any hint.