HI 
I have checked the tutorials at both Non-fungible tokens | Hiro Docs and the one from the clarity-book book/marvin-token.clar at main · clarity-lang/book · GitHub are either incomplete or outdated.
The hiro one doesn’t seem to have a function to let only the owner of the contract mint. It also adds confusing by using a public method “claim” in lieu of mint. The Clarify-lang one is even worse: the token-uri is defined to none which means it won’t show any image at all as it would have no link to the metadata.
I am just wondering if I mix a piece of this puzzle or why such a big project doesn’t have a fully working tutorial to follow through (e.g. set a mint price if needed, allow the public to mint yes/no etc.). At the very least both tutorials should work fine.
Any suggestion on how to get one of these tutorials to work e.g. for the hiro one to have only the author like (define-constant contract-owner tx-sender) to be able to mint?