Uploading a XML file and coverting to JSON to create a database item

I have been searching around to find a way to create new things in my database from uploading a single XML file in the file uploader element.

Everything I see and read is doing API calls to a third party however I will be manually uploading into the app via the file uploader. I’ve seen little on how to create something from XML format so figure its best to import as XML then convert to JSON.

However I am completely lost on how to do this. Any help appreciated!