To use the Image Editor REST API to process image files, you will first need an account with Accusoft Cloud. Once you have a registered account, you will be able to retrieve your API key. This API key provides a simple way to authenticate your requests to the Image Editor API and other Accusoft Cloud APIs. The following example shows how you can supply your API key as the acs-api-key header on any requests made to Accusoft Cloud APIs:

var client = new HttpClient();
client.BaseAddress = new Uri(@"https://api.accusoft.com");
client.DefaultRequestHeaders.Add("acs-api-key", "YourAPIKey...");
var response = await client.PostAsync(apiEndpoint, requestContent);