Al cambiar de Fotolia a Adobe, se ha perdido mi licencia

You need to contact Adobe customer care to see if they can help you. 

However, it may well be, that you can't use the license for your book cover. You will need to check your licence agreement at the time of the licence buy. I do not know if and what licence was required by Fotolia to use the asset on a book cover.

Adobe customer care can be contacted by beginning a secure chat session at https://helpx.adobe.com/contact.html?rghtup=autoOpen. Pop-up blockers need to be disabled, you need to accept cookies! If the chat window fails to open, or is non-responsive, use a different device and/or browser to start the interaction.

For support via Twitter:
https://twitter.com/AdobeCare
For support on Intagram:

https://www.instagram.com/adobecustomercare/

(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
https://community.adobe.com/t5/account-payment-plan/how-to-contact-adobe-support/td-p/11843852)

Important: Adobe does NOT contact you unsolicited by e-mail or direct message. If you get contacted by direct message from a person, claiming to be an Adobe employee, look at that profile and check if they bear the “Adobe Employee” marking under their name. Adobe support does not use Skype to give you support.
If in doubt, ask the forum.