I have a requirement to create Custom SDK Block.
Wondering if anyone of you has done it before if so how to do it.
Also it would be great if you share any reference document for this. (edited)
I've developed a couple of Custom Blocks. It's pretty straightforward and the methods are very easy to use. The best starting point (aside from reading the SDK documentation) would be to install a working demo app so you can see it in action and review the code. Here are a couple of public repositories that you should clone:
Note that the second app requires additional configuration of your installed package (which is not explained in the repo readme). I would encourage you to watch a video that walks you through installing this app this video (fast forward to 11 mins in).