Well, I bought Norton 360 multidevice, I already entred the product key in my computer and laptop, when I was trying to put the product key in my Android it said it wasn't valid, I typed it all lower case first, and after that all lower case with dashes, it still said it was invalid, how do I have to type the product key???
Like this: XXXX-XXXXX-XXXXX
or XXXXXXXXXXXXX
or xxxxxxxxxxxxxxxx
or xx-x-xxx-xxxx-xxx???
Hi Morelittle.
Welcome to the Norton Community Forums. 
I do not have N360 Multi Device myself but I would not have expected you to have to enter a code on the Android device if you have already registered it though your laptop.
Try the following. Uninstall Norton Mobile Security (NMS) from your Android. Reinstall from Google Play (I assume you are getting it from there let us know if you are getting it from somewhere else) and go through the process of registering it again but when offered the option of choosing "I have already purchased this product", take it. That will, I believe, take you through to link up your current licences with the mobilesecurity.norton.com website from which NMS is controlled on your Android.
Do let us know if you try this as it would be good to know if it works. I think it should.
If you have any further questions - just ask.
Thank you for the reply, though I'm replying late, I'm just here to tell you that I already figured it out, it had to be typed all in caps and without dashes. Thank you again for your help, anyways.
Delighted that it is all sorted Morelittle.
And thanks for coming back and giving us the update. ;-)
Well, I bought Norton 360 multidevice, I already entred the product key in my computer and laptop, when I was trying to put the product key in my Android it said it wasn't valid, I typed it all lower case first, and after that all lower case with dashes, it still said it was invalid, how do I have to type the product key???
Like this: XXXX-XXXXX-XXXXX
or XXXXXXXXXXXXX
or xxxxxxxxxxxxxxxx
or xx-x-xxx-xxxx-xxx???