The 1plusX RTD module appends User and Contextual segments to the bidding object.
Compile the 1plusX RTD Module along with your bid adapter and other modules into your Prebid build:
 gulp build --modules="rtdModule,1plusXRtdProvider,appnexusBidAdapter,..."  
Use setConfig to instruct Prebid.js to initilize the 1plusX RTD module, as specified below.
This module is configured as part of the realTimeData.dataProviders
var TIMEOUT = 1000;
pbjs.setConfig({
    realTimeData: {
        auctionDelay: TIMEOUT,
        dataProviders: [{
            name: '1plusX',
            waitForIt: true,
            params: {
                customerId: 'acme',
                bidders: ['appnexus', 'rubicon'],
                timeout: TIMEOUT,
                fpidStorageType: 'html5'
            }
        }]
    }
});
| Name | Type | Description | Default | 
|---|---|---|---|
| name | String | Real time data module name | Always ‘1plusX’ | 
| waitForIt | Boolean | Should be trueif there’s anauctionDelaydefined (optional) | false | 
| params | Object | ||
| params.customerId | String | Your 1plusX customer id | |
| params.bidders | Array | List of bidders for which you would like data to be set | |
| params.timeout | Integer | timeout (ms) | 1000ms | 
| params.fpidStorageType | String | Where to read the first party id (‘html5’ or ‘cookie’) | ‘html5’ |