Nine days ago, I replied to your question about how to return and reactivate the license.
I'm going to rewrite the question again.
"As you explained, I tried to return the license but a screen appears that says "Offline Activation" (At the end of this email I attach the image).
I have tried several ways but I can't.
Please, can you give me detailed instructions on how to proceed?"

Hi Alex,
Thank you for reaching us.
We have registered a case for your request and the case number for your reference is 05042428.
Activation involves confidential details and hence we will not be able to assist you through Forum.
Please respond back to the case email with the requested details, and we will further assist you.
Regards,
Sunil.