Correct endpoint URL is slightly differs: https://xxx.myshopify.com/payments_apps/api/2021-01/graphql.json

Hello. While developing a payments app I'm getting error "Field 'paymentsAppConfigure' doesn't exist on type 'Mutation'". I also checked the endpoint https://xxx.myshopify.com/admin/api/2021-01/graphql.json with a GraphQL client such as graphiql (aft...