Generate a PDF via an API

The following video demonstrates the process of calling an API from the App Designer, which generates a PDF: PDF Designer - App Implementation

Using a JSON content type for the API call from the App Designer to the PDF API is advisable. Otherwise, there’s a risk of encountering a "500 error - too many parameters."
Ajax snippet for the post-operation
let PDFData; // Add here the object with your data.
             // The keys here can be the keys you have defined in
             // the PDF Designer > Settings > Interface

$.ajax({
    type: "POST",
    url: "/pdf/{name-of-pdf}"
    data: PDFData,
    success: function(data) {
        // add your success logic here
    },
    error: function(result,status) {
        // add your error logic here
    },

});