There are thousands of "DJI Webpages" it would be helpful if you would provide the web address for any specific web page you cite.
It saves others having to trawl through various pages and perhaps not look at the one you are looking at.
Ahhh are you perhaps referring to something connected to Care refresh?
If so a google for "dji activation code" found this
DJI Care refresh ACTIVATION code? [Solved] o
n the DJI forum.
Entitled
"DJI Care refresh ACTIVATION code? [Solved]"
or this
Can anyone share your experience in getting your Care Refresh activation code? On 5/23/20, I purchased my DJI Care Refresh for my
Mavic Air 2 right after I received and activated my new drone. I received the DJI Care Confirmation service agreement through an email quickly with the specified...
forum.dji.com
entitled
"Care Refresh Activation Code"
There were numerous other articles listed in the search results.
It may be that the activation code is ONLY needed if you want care refresh, my
mini 2 has flown perfectly happily with out it.
Is there a message that you are seeing in the app? If so post a screen capture of that message, a screen capture will possibly be more informative than a quotation of something on that screen.
If you DID NOT have to activate the drone then you CAN NOT get care refresh 'off the shelf', you will have to provide DJI with a "verification video" and other stuff.
Google etc. " DJI care refresh verification video".