You can change the time interval of statistical data, such as on the Charts tab of your Shelly Device. Adjust the time interval by choosing the Hourly time filter from the dropdown menu located above the corresponding chart.
For users on the Basic Plan, statistical data will be visualised in 1-hour intervals.
For users on the Premium service and the Free trial, statistical data will be visualised in 1-minute intervals.
Source: https://kb.shelly.cloud/knowledge-base/premium-service#PremiumService-PremiumBenefispremium-benefits
Note: You can visualise and download the statistics only for specific hour at a specific day. You cannot visualise/download 1-minute intervals for a bigger period - whole day, week or month.