let axios = require('axios')

let getShipmentDetails = async (url) => {

        var res = await axios({
            method: 'post',
            url: url,
            headers: { Authorization: "<Bearer token>"},
            data: {
                "filter" : {
                    "type" : "postDispatch",
                    "states" : ["Delivered"],
                    "orderDate" : {
                        "from" : "2022-03-02",
                        "to" : "2022-03-10"
                    }
                }
            }
        })

        if (res['data']['hasMore'] == true) {
            var newurl = "https://api.flipkart.net/sellers"+res['data']['nextPageUrl'];
            console.log(newurl)
            let more = await getShipmentDetails(newurl)
            return res['data']['shipments'].concat(more);
        }
        else {
            console.log(res['data'])
            return res['data']['shipments']
        }
}

getShipmentDetails("https://api.flipkart.net/sellers/v3/shipments/filter/")
.then(result => {})

The newUrl is same everytime. I cannot able to access content of next page in results.

Documentation

res['data']['nextPageUrl'] = /v3/shipments/filter?next_token=ewogICJmaWx0ZXJUeXBlIiA6ICJwb3N0RGlzcG......GF0ZSIgOiAib2FwaV9wb3N0X2Rpc3BhdGNoIgp9