You can find our guide on publishing Lenses to profiles on our business support site. Link

NOTE: You must be a profile admin to publish a Lens to another user's account. If you are the owner of the account, you can publish your Lens through the typical Community Lens publishing method.
To add a Profile Admin: go to My Profile > tap ⚙️ > Manage Roles > Assign New Role > enter the username of the assignee and select Profile Admin

Alternatively, your client can transfer the Lens from their Ads account to their public profile if it was published as a Business Lens previously. Please see our guide to publishing Lenses to profiles for more info. Link