How to add text after the first line in notepad++ in all open documents?

Question

Notepad++

You need to add text right after the first line. There are a lot of files, I tried this: Replace: ($) With: text / 1 It worked but at the end of the line and when trying to replace in all documents, the text was inserted at the end of each line. Help whoever can))
Example:
1.TextTextTextTextTextTextText
2.TextTextTextTextTextText<--------Here you need a different text with a line shift down in all open documents 3.TextTextTextTextTextTextText

Answer 1

(?s-m)^(.+?\n)(.+)
$1другой текст\n$2