1. After setting request method to POST, click to the 'body' tab.
2. Select form-data. At first line, you'll see text boxes named key and value. Write 'image' to the key. You'll see value type which is set to 'text' as default. Make it File and upload your file.
3. Then select 'raw' and paste your json file. Also just next to the binary choice, You'll see 'Text' is clicked. Make it JSON.