Hi K2Developer,

Perhaps 'Visual Studio Project templates' is what you have to install? I'm not quite sure but perhaps this article linked below may help you achieve your goal:
https://community.k2.com/t5/K2-blackpearl/Visual-Studio-Project-Templates-for-K2-blackpearl-Extensions/ba-p/1081?nobounce

Regards,

Sello

Can you specify more details what exactly your  trying to do. Are you on k2 4.7 or k2 5 + version?

Good day K2Developer-1

I have listed documentation below you can review which will take you through all the steps to add K2 to your Visual Studio. I hope this will answer your question in how to add the k2 extension. Note this documentation is on k2 blackpearl 4.7.

Documentation:

https://help.k2.com/onlinehelp/k2blackpearl/icg/4.6/webframe.html#install_k2forvisualstudio.html

Best Regards 

Jacques.

Hi

I have attached the link that will help you about anything related to K2 Extensions, please go through all the link below:

http://k2.com/training/BP2
Http://k2.com/training/BP2/HandbookPDF
http://k2.com/training/BP2/ExercisePDF

Dont forget to mark this as KUDOS  and solusion or only KUDOS if this article is helpful.

Regards

Elvis