@nielsk There are a lot of broken links over there, unfortunately, but most pages still exist on new URLs. The one you're looking for is probably Copying photos to Micro.blog from Instagram.

You should notice, though, that OwnYourGram is more or less defunct. So probably better to use another solution, like this one by @jarrod.

@sod that page is mentioned as an example how to connect to the api with an application. I use it with another app