I recently went through these exact pains trying to contribute to a project that exclusively ran through Discord and eventually had to give up when it was clear they would never enable issues in their GitHub repos for "reasons."
It was impossible to discover the history behind anything. Even current information was lost within days, having to rehash aspects that were already investigated and decided upon.
Even if it didn't outright display the code you need to enter, my guess is this and similar implementations hide further vulnerabilities like: the numbers aren't generated with a secure random number generator, or the validation call isn't resistant to simple brute force quickly guessing every possible number, or the number is known client side for validation, etc.