write back data from power Bi services in onedrive excel sheet

HI Puja_Kumari25 ,

I think you are using a couple different terms here.  Write back is where Power BI will create data based on the report and UPDATE (write back) to the original data source.  There are some third party tools and there is Power App capability to do this.

The second sentence is about inserting data.  So, yes, you can take data from Power BI service and using Power Apps you can export that data to Excel,.  

There are plenty of links out there on how to do this and I will not try to recreate them here because as soon as you start, there will be numerous "unique to your environment" decisions that other entire articles are devoted to discussing.