I know how to add an image file in question post like this, but I need to add a very wide txt file and I am strugling for this.
Please, what I'm missing ?
If I click on image insertion button I can insert only image, but for the .txt?
You cannot attach a file, like you would in email. That isn’t supported. You have a few options:
Note: I would encourage anyone that thinks they need a file so big it won't fit in a code block to consider (1) if the question would be useful to others and (2) if that specific data is needed. For example, if it is just "How can I read a 12GB CSV file?", the specific contents of your CSV file is irrelevant. If the file contents really is important to the question, consider archiving the pastebin (or direct download, if one) with the Wayback Machine in case the original page goes away
But do consider this first: do you really need to include the entire file? Would your question be fine without it? If it isn't needed, don’t add it. Also, depending on the question, adding a portion of the file could work.