API Public Character Retrieval

Hi I am using a public API to retrieve data from a server. The API is a GUI and I'd like to know what characters I should try to put in the string value of e.g. postal codes in order to retrieve all the value of the dataset. It could be a '*'. or '%' or '#' or something like that. I tried everything but it does not work. This field / string returns values such as postal codes from a dataset. If I leave it blank, I get nothing. I need to fill this field with a postal code to isolate my readings per that postal code. I do not want that. I do not want to isolate per postal code. I want to get all values for all postal codes that exist in the dataset. So how do I do that? What should I write in this field to return all postal https://omegle.club https://chatrandom.download/ https://azar.pro codes? Thanks in advance