Shopify does not allow direct removal of the robots.txt file
Shopify automatically generates robots.txt for every store
You can only customize it, not delete it
Go to Shopify Admin
Click Online Store
Click Themes
Click Actions
Click Edit code
Add or edit a robots.txt.liquid file in the theme code
Use Shopify’s robots.txt.liquid template to control directives
Remove unwanted rules by editing the file content
Save the changes
If you need the default Shopify robots.txt behavior restored, delete the custom robots.txt.liquid file
Contact Shopify Support if you need platform-level changes
Use Google Search Console to request reindexing after changes