Yes, that is possible. All you need is a monthly plan (other than our free plan) or a prepaid plan of (net) 11.15 USD. As soon as you are on such a plan you can deactivate the logo in the settings section of your forms.
First open the form in question and click on [Settings] > [Information].
There you need to scroll to the bottom of the screen and uncheck [Show advert]. As soon as the box is unchecked and the form is saved the logo will no longer be shown in the forms as well as the opt-in emails.
If this functionality is deactivated you are not on a paid / prepaid monthly plan. As soon as you have one of these plans you will have access to this functionality.