Hi Rudi,
It looks like you’re trying to upload a file it’s actually easier to copy paste the code into the forum post.
You can either surround your code with the tthree backticks manually as James mentioned, like this:
```
Your code here = x
Some more = code
and some more
```
Or you can make sure it’s surrounded by empty lines and use the code block button: 
Your code here = x
Some more = code
and some more
Here’s what it looks like on your end:
Even if it’s a large amount of code, don’t worry as the forum will take care of all the formatting, and make it nice and neat.
