Select the 3 dots at the top right corner of the patient record and then select edit details:
If you click on 'Edit' on your Patient record it will display the 'Edit Client' screen. To edit consent you will need to go to the 'Consent Details' section.
From here the you can select the level of consent that the patient has given including how they would like to be contacted in regards to marketing information.
Once these have been selected and saved a summary of the Patient's consent can be seen within the left hand menu of the Patient record.