How do I add custom button in the player

Hello Seema, 

Thanks for reaching out! 

There isn't a way to create a custom button that is always visible in a Rise 360 course. As an alternative, you can add a button block to your Rise 360 course and link it to your sign up page: 

I’ll be happy to pass your thoughts on to our product team, but you can also feel free to detail them more through a feature request!