Wrong sequence of lessons!

Hello Community,

There is a lesson: https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/regular-expressions/restrict-possible-usernames/

And while passing it I was wondered how I have to solve it. The reason why I got stuck was this task:
3) Usernames have to be at least two characters long. A two-letter username can only use alphabet letter characters.
After a couple of minutes of thinking I decided to GET A HINT and here is what I’ve found there:
Usernames have to be at least two characters long. {2,}

Since I have learned nothing about {2,} this technique before it is impossible for me to pass the task! Then I decided to check the curriculum and it appeared that I will learn about it but a couple of lessons later here: https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/regular-expressions/specify-exact-number-of-matches/

Here is a demonstrative screenshot:

Please fix this if it was not noticed before by someone else.

Suggested solutions are written by volunteers over time. They do not always include a very comprehensive range of solutions. The solution that is currently in the Guide is not the only way to solve it, just the one that was suggested by the community members who helped write that Guide page.

What is another solution?

There are a number of ways to solve this. If you only use the tools that FCC has explicitly taught you already they are less elegant, but you can do it.