document.writeln() method does not write in a new line
writeln(): write a string of text and add a newline character after each statement.
but when you write string inside multiple writeln() method, you observe that writeln() doesn't write to a new line.
This is because all whitespace is converted into a single space when rendering into HTML that why your newline does not work inside your HTML file.
if you want your writeln() method write to a new line, for that write code inside pre tag, for example
<html> <body> <p>kept writeln inside pre tag</p> <pre><script> document.writeln("Hello everyone1"); document.writeln("Hello everyone2"); </script> </pre> </body> </html>