You can change the Date format by editing the Code in the Liquid tab.
The code is
{ order.created_at | date: 'MM/DD/YYYY' }} and it will show like (04/18/2020)
the symbol in it is know as:
+ M: Month
+ D: Date
+ Y: Year
The number of symbol is the amount of symbol will show.
('D/M/YY' => '1/10/20')