liberland
Correct some errors
It seems ok for me.
Just one point : fulfil is ok (english), but fulfill is also ok (US). Since fulfill is the most common and is used eg in the Constitution, I'll recommend keeping fulfill.
Liberland uses Oxford English for all communication, so using US English wouldn't make sense. Not to mention one should not be mixing varieties of English, as that looks unprofessional.
Where is it mentioned that Liberland uses Oxford English, please ?
https://liberland.org/en/about mentions only : Official language | English
And, as said, many already written docs use "fulfill". We'll not begin to change that I guess.
The about page only mentions the official language of communication (not necessarily written communication), in the same way the US's official laws don't say that they'll use US English, but just "English", and the UK's laws don't mention that they'll use "British English", but just "English". Conventionally, however, it's assumed that the US will use US English, the UK will use British English, Canada will use Canadian English, etc.
Similarly, if you look at the website or any of the news articles, you'll notice it uses Oxford English (e.g., favour but organize, etc.). It has been the policy of Liberland basically since the beginning.
If there are other places where "fulfill" is being used, those will need to be changed. Could you point to where those are?