Why won't my GraphQL request work in Shopify app development?

[Mahdibn]

Hi, i'm a beginner in shopify app developement so i followed the shopify tutorial but i couldn't get the product data using a graphql request (i used the exact code mentionned in the tutorial).

i get this error :

Can anyone help me find out the reason i'm getting this error or a fix in my code?

thanks in advance.