How to align some of the content to the center and some to the right side using flexbox?

Question

css

https://jsfiddle.net/1cbef6kL/4/
how to align blocks with class register and number to the right side and leave everything else centered? How to do it with flexbox?

Answer 1

margin-left: auto for penultimate item

Answer 2

justify-content: space around;

Answer 3

.register {
position: absolute;
right: 0;
}
Only with the help of flex boxes I did not succeed.

Answer 4

https://tproger.ru/translations/how-css-flexbox-works/