Why can't images be transferred from tmp on hosting?

Question

ubuntu

Good afternoon.

There is such a problem, I was given access via FTP from the subcategory where I uploaded the site. This site accepts files and must save data to an internal folder.

I don't have root access.

The problem is that I don’t have to check whether the data is saved in TMP. But obviously there is a problem, because

move_uploaded_file($file['tmp_name'], $path . $name)

returns false.

At the same time, the script works perfectly on my server. Where to even look?
Also on client hosting, I can't use constants, including (__DIR__)