Hi @Harmanpreet,
Could you please share a bit more about your custom connector?
Could you please show more details about the response your custom connector returned?
Further, do you want to insert the output of the custom connector into your Google sheet?
Please check if you have specified proper File and Worksheet in your "Insert row" action. Please also check if the output your custom connector returned is proper.
You could consider view the run history of your flow, then expand the "DataFetch" action (your custom connector) to see the output the custom connector returned. Check if the Dynamic contents the custom connector returned contains proper values.
In addition, please check if you have specified proper "x-ms-dynamic-values" OpenAPI extension within the OpenAPI for your custom connector. More details about the "x-ms-dynamic-values" OpenAPI extension, please check the following article:
"x-ms-dynamic-values" OpenAPI extension
More details about customizing connector in Microsoft Flow, please check the following article:
Custom connector in Microsoft Flow
Best regards,
Kris