how pass query variables to client in every request ?

[namdroid]

Question

my request shows like that:

curl --request POST \
 -H 'Content-Type: application/json' \
 --data '{"query":"query GetBestSellers($category: ProductCategory){bestSellers(category: $category){title}}", "operationName":"GetBestSellers", "variables":{"category":"BOOKS"}}' \
 https://rover.apollo.dev/quickstart/products/graphql

How can i pass "variables":{"category":"BOOKS"}} ?