 Hello there. In this video, we will see how RESTful Web API takes the advantages of JSON to perform its various tasks. When the REST APIs emerged as a less complicated and equally capable alternative of SOAP-based web service, people were started talking about other mediums for data interchange other than XML. And this is where JSON began to gain momentum. My Scout have also provided PDF.co RESTful web API for document manipulation, data extraction, data conversion, and so on and so forth. Almost all of the PDF.co web API endpoints uses JSON as input to perform various tasks such as intelligently extract data from PDF or .x file with preserved formatting or you can also convert your PDF file to CSV, XLS, JSON or HTML and so on. Now let's perform one demo and see how PDF.co web API can create fillable PDF form from an existing PDF file by adding editable text boxes and checkboxes etc. So this is the endpoint URL using which we can achieve this requirement. Well, we will use Postman to run this API. So let's open the Postman and let's try to understand its input JSON parameter. And by the way, you can download this API's request collection from this link. Now let's open the Postman to see this API in action. All right. Now here in the Postman, let's go through the input parameters in JSON. So as you can see here that we have a JSON object where there are different parameters like what is the name of the newly generated document after manipulation. And this is the URL which of course points to the physical PDF file. Now let us open this PDF file. All right. So this is the PDF file on which we perform this operation. Let me scroll down a little bit. Now this annotation part is an area in which there is an actual operational parameters like at this X and Y coordinate. I want to add the text box filled with this predefined sample text. And this is the ID of the text box which I want to set. And then let me scroll down. So now at this X and Y coordinate, I want to set the checkbox with this particular ID. Now let us scroll down a little bit. Same way you can also set the multiple images on the PDF by specifying its path in the images area like this. So in this JSON object, first you need to set the URL of the images like this. And then you need to specify the X and Y coordinate where you need to set the image. And same way you can use this type of multiple JSON object to set multiple images in the PDF. Now it's time to invoke this API. But before you run the API, you need to set the API key in the request header. I have already set my registered API key in the request header. Now it's time to run this API. So for that, you need to click on this send button. And here we have our API response. You can see that our API response is in JSON format. This is our newly generated document name. And this is the URL where our newly generated PDF is resided. So let us open this URL. So as you can see here that this is our pre-filled sample text at this particular X, Y coordinate. And here is the another checkbox with check property set to true. And this is the image which we have set in the image area. So this is how using PDF.co web API, you can add an editable text box or checkbox or radio button in the existing PDF file. All right, now let's move to the next part.