Setup apollo graphql server for VS code

Hi, Im looking to setup apollo graphql extension in VS code, I've read the other similar issues and have tried all combinations in the apollo.config.js file with no luck, the documentation has detailed info on client setup but could not find for server, please advice?

I have the apollop.config.js as

module.exports = {
    service: {
        localSchemaFile: 'graphql/schemas/*.graphql',
        // excludes: ['node_modules/**/*'],
        // includes: ['**/*.graphql'],
    },
};

I have 6 .graphql files under ./graphql/schemas

./graphql/schemas/checkout.graphql
./graphql/schemas/device.graphql
./graphql/schemas/otp.graphql
./graphql/schemas/plan.graphql
./graphql/schemas/porting.graphql
./graphql/schemas/root.graphql

My root.graphql looks like

type RootQuery {
    OTP(msisdn: String): OTP
    operator(msisdn: String!): Operator
    portingTime: PortingDateTime
    plans(planIds: [String!]): [Plan!]
    securityQuestions: [SecurityQuestion]
    customerDetails(prospectUuid: String): CustomerDetail
    deviceList(catalogOfferId: String): [Device]
    deviceDetails(deviceId: String): DeviceDetails
}

type RootMutation {
    validateOTP(otpUuid: String!, otp: String!): Boolean!
    createPortIn(portInInput: PortInInput): String
    updateCustomerDetail(
        prospectUuid: String
        customerDetailInput: CustomerDetailInput
    ): CustomerDetail
    termsAndConditions(
        prospectUuid: String
        termsAndConditionsStatusInput: TermsAndConditionsStatusInput
    ): TermsAndConditionsStatus
}

schema {
    query: RootQuery
    mutation: RootMutation
}

and my otp.graphql looks like

type OTP {
    otpUuid: String
}

Auto complete does not work and I see this in the logs

(node:13000) UnhandledPromiseRejectionWarning: Error: Unknown type: "OTP".
    at getNamedType (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\utilities\extendSchema.js:355:13)
    at getWrappedType (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\utilities\extendSchema.js:370:12)
    at buildFieldMap (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\utilities\extendSchema.js:404:17)
    at fields (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\utilities\extendSchema.js:554:22)
    at resolveThunk (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\type\definition.js:478:40)
    at defineFieldMap (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\type\definition.js:690:18)
    at GraphQLObjectType.getFields (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\type\definition.js:631:27)
    at collectReferencedTypes (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\type\schema.js:366:81)
    at new GraphQLSchema (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\type\schema.js:148:9)
    at Object.extendSchema (d:\Users\savishnu\.vscode\extensions\apollographql.vscode-apollo-1.16.8\node_modules\graphql\utilities\extendSchema.js:82:53)
(node:13000) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 37)

Start with apollo.config.js and the schema files under graphql/schemas, especially root.graphql and otp.graphql, then trace how the VS Code extension loads and combines them. Confirm the schema is accepted without the Unknown type: "OTP" error and that autocomplete works across the files.