How to use angular's $http to submit a form (including File type), and can the backend PHP obtain it using the $_FILES variable?

I want to upload a file, select a zip file, and pass it to the background php file through ajax. The php file can use $_FILES to get the file, but I don’t know how to implement it.

I tried not using $_FILES before, but using the following method to save the zip file

<code>$input = file_get_contents("php://input",true);
file_put_contents('temp/olin.zip',$input);</code>

However, although the saved olin.zip file can be opened normally in the resource manager, there is a problem with the zip operation of php. Both zip_read and close will report errors. (The zip file generated without the above two lines of code can operate normally)

Please tell me how to read $_FILES, or use php://input to generate a normal zip file.