Hi there and welcome
Retrieval depends on where and when you puchased it
If you have a parelles account then
If you lost your activation key, you can try to retrieve it by logging in to your Parallels account here (https://account.parallels.com/). If you cannot log in or do not remember the password ***** your Parallels account, please retrieve the password ***** https://account.parallels.com/#/restore
Click on the subscription/license you need, then click on the Keys button to see the activation key.
If you purchased Parallels Desktop for Mac from Parallels Online Store after August 12, 2012, please click HERE to retrieve your key.
Purchases made at Parallels website between June 21, 2010 and August 12, 2012 can be looked up HERE
In case your order for Parallels Desktop was placed at Parallels Online Store before June 21, 2010, please contact CUSTOMER SERVICE HERE
If you have any problems, or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.