This post OG is my Lemmy account, here is my another test post which is created by using a Mastodon account https://lemm.ee/post/6301537

Here is what I had found on the Internet to do and I actually did it: To comment a post, you just copy the link of the post, to comment a comment, you copy the link of comment, it has a button looks like a chain, once finished copying, paste it to Mastdon. To create a post, I use this way:

@community@instance Title

Content

But it will create an ugly ping link to the community