Code:
javascript:(function(){var e=document.createElement("input");e.type="file",e.onchange=function(){var t=new FormData;t.append("files[]",this.files[0]);var n=new XMLHttpRequest;n.open("POST","https://files.offshore.cat/api/upload",!0),n.setRequestHeader("x-api-key","kwMcLy1tPHKD9M2f0csozJkWuAaQopjQ6yKQb2MvS7czwbGw2aM9PukH8cMVSloZ"),n.onload=function(){if(200===n.status){console.log("File uploaded successfully!");var e=JSON.parse(n.responseText);alert("Uploaded file link: " + e.url)}else alert("An error occurred while uploading the file.")},n.onerror=function(){alert("An error occurred while uploading the file.")},n.send(t)},e.click()})();

Save the code as a bookmark to have this feature directly on your browser.