If you'd like to add a subscribe prompt to your links it is quite easy.

Copy your YouTube profile link.

Append to the end of it 

?sub_confirmation=1

Then save the link. 


So if you do not have a custom channel name it might look like this:

https://www.youtube.com/channel/UCGBl1CZRE4v5lU3WVvzuOzQ?sub_confirmation=1


Visitors will be prompted to subscribe when they open your YouTube Channel.



Video walkthrough: