I’m guessing the issue is that the files you’re trying to upload are over the file size limit, yes? And that them being deleted is what’s resulting in the 404 error? If so, there’s no way to circumvent the file size limit, doing so may count as abusing InfinityFree’s services, and it’s not something you could do with a .htaccess file anyways. The limit for file sizes is something that’s set on the server level and not just a PHP configuration. Please take a look at the following article for more information.
Depending on the files and why they’re above the limit, you may be able to optimize them or break them down into multiple smaller files.