Yes, you can, but only at an Avada support level. To clarify, whoever purchases the license via Themeforest is the rightful owner of the license. According to Envato, ownership of a license can’t be transferred between individuals or marketplace accounts. At an Avada support level, however, the following scenarios are possible:
If you have not registered the purchase code within your My Avada account, you can request that your customer registers their own My Avada account using the provided purchase code by following these instructions.
If the purchase code is already added to your My Avada account and you would like to pass it on to your client so that they can register their own My Avada account, you can remove the purchase code from the Licenses page by clicking the bin icon next to the relevant purchase code.