Can you please provide the requested information per the Posting Guidelines.
https://wp.storelocatorplus.com/forums/topic/looking-for-technical-support-from-the-slp-team-in-the-forum/
After you created the Google sheets file did you download it to a CSV file and save it where you could access it, in a local directory and then upload it?
The minimum info we need to assist you:
A screenshot of your Plugin environment found under the SLP/INFO tab is best, it shows us
the SLP and WP and PHP versions, including the SLP add-ons you may have. Best method to provide this info is to capture a screenshot , under the Info tab ,
If it would be useful, please also
provide the site url page where you have the SLP locator activated
If you have a debug log please include any error information.
I cant see into your site, nor your computer , to assist you so I am afraid I need more info in order to help you.
If you are sure you have a properly formatted csv file, Check to see if your server is preventing the wp-cron.php from being triggered.
You might be able to see what the issue is after reading the IMPORT process
https://docs.storelocatorplus.com/blog/power-import-and-wpslp-4-9/
https://docs.storelocatorplus.com/blog/location-imports-with-power-add-on/