file slice blob upload

[nimei66]

 while(start < totalSize){

        fd = new FormData();

        xhr = new XMLHttpRequest();

        xhr.open('POST',util.config.serviceUrl+'/test',false);

        blob = file.slice(start,end);

        fd.append('data',blob);

        xhr.send(fd);

        start = end;

        end = start + LENGTH;

    }

When the blob was uploaded by the front-end slice, the program did not run properly

[GIN] 2022/11/22 - 00:16:12 | 200 | 16.1792ms | 127.0.0.1 | POST "/test"
form not found
[GIN] 2022/11/22 - 00:16:12 | 200 | 17.023ms | 127.0.0.1 | POST "/test"
form not found
[GIN] 2022/11/22 - 00:16:12 | 200 | 15.1288ms | 127.0.0.1 | POST "/test"
form not found
[GIN] 2022/11/22 - 00:16:12 | 200 | 13.3188ms | 127.0.0.1 | POST "/test"