Server communication over Raspberry

I am trying to make an Arduino communicate to a Server over the Internet. I am using an Arduino Uno connected to a Raspberry Pi 4B. The problem is that I do not if it even possible, the goal of the whole thing is to have a website from which I can control the Arduino and read Data from it (Serial). I know about IOT Cloud, but it wont work because my Arduino isn't IOT compatible. The connection to the Internet/Server should run over the Raspberry Pi. It is important to note that the raspberry is not the server that should host the website, it is only the "gateway" for the arduino.
I am looking forward to your answers!

It's plausible and you can do it as a set of sub-projects:

Get the Uno sending data to the Pi
Get the Pi scraping the website.
Have the Pi send command data to the Uno.

You can test each independently and combine them at the end. Your Uno code will be C++ but the can use whatever suits you on the Pi.

Thanks for the quick answer!
I already settled the communication Arduino -> Pi, I use a python script to read the serial data. Now how do I send the Data to a server from now?
Thanks again!

Curl is an easy way to get started sending data.

You write some Python code to rederive the Arduino data, which you indicate you've done.

I have 9 ESP32's sending data to a RPi. The RPi sends data to and from my websites server.

I dislike Python and thus know little about it, but I expect that there are libraries to assist you with talking to a web site.

If not, I have a Pi that gets weather data from a remote site using a system call in Perl to curl and then parses the JSON returned string. You could presumably do the same thing in Python.

I just dont get how I connect the raspberry to the server and back, I cant get my mind around that. Could you please a bit more in depth?

Isn't a discussion about the RPi better served on the RPi site?

Yeah I am gonna try it there, thank you