"Script" to upload files to a site using Java?

Question

JavaScript

Tell me what you need to implement the "script" (program) that will upload files to the trading platforms instead of me) The work is not related to programming, I just want to delegate the routine to the computer. I'm learning Java at the same time.
Does the Java world have tools for this? Or is it better to use JS features?
The first thing that came to my mind was to use Jsoup, there seems to be a Post method where you can pass the inputstream. The first attempts were unsuccessful) How to make the script use my browser or be logged into the desired site.
How to specify the required form for sending, there are not many of them?
Tell me where to dig, what topics to study ?!

Answer 1

How do I make the script use my browser or be logged into the desired site.

Selenium + any browser (chromium, firefox) + drive for that browser.
Launch the browser in headless mode and do whatever you need (download files, etc.).
If you need to run the task regularly, then add a system process.
But in my opinion, in your case, it would be better for a scripting language to implement this. A la js, python.

Answer 2

It is possible in php, here is a link to the code:
In JS and Java, this cannot be done in my opinion.