Here are two methods to activate the software, see below
Method 1 Create Wondershare ID account with the email address which you used to purchase this software. Please refer to below screenshot.
Method 2 Type the register code directly without signing with Wondershare ID account. Here is the screenshot you can refer.
You can use the same Wondershare ID account to activate Filmora9 through online or offline activation.
Actually, Filmora8 and older versions are totally different from Filmora9. Filmora9 will not replace your older versions, so they can be installed at the same time and saved on your computer.
There is dark skin for Filmora9 and above on Mac, but there is no dark skin if your version is older than Filmora9.