Hi @KavithaAnand
There would be two components of this flow design
1. Cloud flow (for making a scheduled run)
2. Desktop flow ( for doing UI Automation of power bi desktop application)
Let's first talk about Power BI Desktop application
Here create a desktop flow which does the following
1. Launch Power BI Desktop
2. Click Refresh button
3. save and close the report
4. Close the application
NOw once the desktop flow is created, use cloud flow , i.e scheduled cloud flow to create scheduled cloud flow to run desktop flow like below


Hope this information helps !