If you want to change your Domestika PRO subscription to Domestika Plus to enjoy the Plus benefits, you can request to upgrade your subscription in the Subscriptions section of your account on the website. There, you will find the Domestika Plus section with information about the subscription and the option "Upgrade to Plus".
Please note that when upgrading from Domestika PRO to Domestika Plus, only the yearly payment mode is available, which is done through a one-time payment. Like Domestika PRO, the Plus subscription lasts for one year starting from the moment of purchase and will be renewed automatically. However, at the end of the one-year period from the time of switching from PRO to Plus, you can opt for a monthly subscription if you wish. If you want to switch from PRO directly to Plus monthly, you can do this once your PRO subscription is over. More information can be found here.