How to Add Subscribe Link to YouTube Channel and Videos in 2018
У вашего броузера проблема в совместимости с HTML5
How to Add Subscribe Link to YouTube Channel and Videos in 2018 https://youtu.be/w1VaeZzspEo video lesson shows 2 different ways for adding subscribe option for YouTube videos
add
?sub_confirmation=1
to the end of your YouTube channel URL and edit links to insert this subscribe confirmation link option for your channel visitors.
End screen and annotations also allow you to add subscribe option to individual YouTube videos
more insights for adding subscribe button to YouTube videos
https://support.google.com/youtube/answer/6147757