purchased from opencart.com 

and in .zip there is no license key

where to find?

Hello Emilia,

Thank you for reaching us.

You can find the license key for a product in your purchases screen here at iSenseLabs - http://isenselabs.com/users/purchases. However, if your product purchase is not listed there, it is probably not attached to your account. This usually happens when you create an account at iSenseLabs, using an email different from the one you have purchased the extension from the OpenCart extension store.

Since, this is a public forum, I would advise you to open a support ticket, containing your Purchase ID and your username/email. Once the purchase is verified, we will connect it to your account and a product license key will be provided to you.

Hope this helps.