(here's the link -> https://blog.cloudflare.com/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography)

And there was every details provided, except about the Extended Euclidean Algorithm. I found text ->

"Let's make this more concrete with an example. Take the prime numbers 13 and 7, their product gives us our maximum value of 91. Let's take our public encryption key to be the number 5. Then using the fact that we know 7 and 13 are the factors of 91 and applying an algorithm called the Extended Euclidean Algorithm, we get that the private key is the number 29"

And when I passed 5 and 91 into a python implementation of Extended Euclidean Algorithm, which I found on the internet, it's not giving me the result of 29. Maybe I have done something wrong, but I think the blog should have given more details about the Extended Euclidean Algorithm

Here's where I got the python implementation -> http://anh.cs.luc.edu/331/notes/xgcd.pdf

Or here, in case if you don't prefer HTTP -> https://www.geeksforgeeks.org/python-program-for-basic-and-extended-euclidean-algorithms-2/

Could anyone let me know where I'm going wrong and how exactly to get my private key from the public key and the max value?