Changes in Person-reported Outcomes and Behavior Using the Accu-Chek SmartGuide CGM and Predict App

The goal of this controlled pre-post-trial is to test the Accu-Chek SmartGuide continuous glucose monitoring (CGM) system and whether its predictive features provide additional benefits for adults with type 1 diabetes or insulin- treated type 2 diabetes. The main questions this study aims to answer are: * Does using the Accu-Chek SmartGuide together with the Predict App change participants' fear of hypoglycemia? * Does the Predict App affect other psychological and behavioral outcomes, such as sleep quality, confidence in preventing hypoglycemia, diabetes- related distress, and diabetes empowerment? * Does the use of the predictive features affect glucose levels and the way participants use and respond to CGM alarms and trend information? Participants will use the Accu-Chek SmartGuide for 6 weeks. During the first 2 weeks, participants will use the CGM system without the predictive features. During the following 4 weeks, participants will use the system together with the Accu-Chek SmartGuide Predict App. Participants will complete online questionnaires at two time points (after 2 and after 6 weeks) and answer short questions twice a day through a smartphone app during the first 2 weeks and the last 2 weeks of the study. CGM data will be collected throughout the study. A subgroup of 10 participants will also be invited to take part in an online interview about their experiences with the predictive features.