According to the official registration guide , keep these formatting rules in mind:

: You can buy a license directly from the Macroplant shop.

: Codes display "i" in lowercase to distinguish them from the number 1 or lowercase "L"; they will automatically convert to uppercase when pasted.

: Valid codes never contain the number 0 or the letter O.

I lost my registration code. How do I recover it? - Macroplant

: Always copy and paste your code to avoid typos like mistaking a "5" for an "S".