Online or paper CPPD application?

What is better option to apply for CPPD? I was going to do paper copy but then concerned about it getting lost in mail so my cousin suggested doing it online. Are you able to fill it out easily online? Can you save it and come back to it? Can you leave areas blank or add context where needed?

I did paper before online was available.
I would do it online.

I filled mine out online then printed and dropped of at a Service Canada office. It then goes out in the inter office mail which is secure and they receive it much faster.

Thanks for replies. I ended up doing paper copy sent it through mail to service canada. Hoping it won’t get lost.