Hello,
I use a Einstein Bot inside Salesforce Community.

The goal is: The Bot have to provide informations about a specify Order. The order Id is passed by a url parameter. 

In the moment: The PreChat Component recognizes the param and represents it to the user. But how can I store this id to a custom field inside the LiveChatTranscript record to use it inside the Bot?
As a basis, I used the code from this side: https://developer.salesforce.com/docs/atlas.en-us.snapins_web_dev.meta/snapins_web_dev/snapins_web_lightning_components_prechat_sample_aura.htm
Component:

<aura:component implements="lightningsnapin:prechatUI" description="Sample custom prechat component for Snapins. Implemented using Aura." controller="EinsteinBot_SaveRecordeController">
    <!-- Source: https://developer.salesforce.com/docs/atlas.en-us.snapins_web_dev.meta/snapins_web_dev/snapins_web_lightning_components_prechat_sample_aura.htm -->
    <!-- You must implement "lightningsnapin:prechatUI" for this component to appear in the "Prechat Component" customization dropdown in the Snapins setup. -->

    <!-- Prechat field components to render. -->
    <aura:attribute name="prechatFieldComponents" type="List" description="An array of objects representing the prechat fields specified in prechat setup."/>

    <!-- get url parameter -->
    <aura:attribute name="isOrderParamInsideURI" type="Boolean"/>
    <aura:attribute name="orderIdLabel" type="String"/>
    <aura:attribute name="orderIdValue" type="String"/>
    
    <!-- Handler for when this component is initialized. --> 
    <aura:handler name="init" value="{!this}" action="{!c.onInit}" />

    <!-- For Aura performance. -->
    <aura:locator target="startButton" description="Prechat form submit button."/> 
    
    <!-- Contains methods for getting prechat fields, starting a chat, and validating fields. -->
    <lightningsnapin:prechatAPI aura:id="prechatAPI"/>
    
    <h2>Prechat form.</h2>
    <div class="prechatUI">
        <div class="prechatContent">
            <ul class="fieldsList">
                <!-- Look in the controller's onInit function. This component dynamically creates the prechat field components. -->
                {!v.prechatFieldComponents}

            </ul>

            <aura:if isTrue="{!v.isOrderParamInsideURI}">
                <p>
                    more information About the Order:
                </p>
                <p>
                    {!v.orderIdValue}
                </p>
            </aura:if>
        
        </div>
        <div class="startButtonWrapper">
            <ui:button aura:id="startButton" class="startButton" label="{!$Label.LiveAgentPrechat.StartChat}" press="{!c.handleStartButtonClick}"/>
        </div>
    </div>

</aura:component>

...
/**
     * get order Id out of uri
     * TAKE CARE: static implementation for a Demo version
     */
    getOrderIdFromURI: function(cmp, evt, hlp) {
        var isParamInsideURI = false;

        var orderParam = decodeURIComponent(window.location.search.substring(1));
        var orderParamParts = orderParam.split('=');
        if(orderParamParts.length == 2){
            var orderParamLabel = orderParamParts[0];
            var orderParamValue = orderParamParts[1];
            isParamInsideURI = true;

            //set attributes
            cmp.set('v.orderIdLabel', orderParamLabel);
            cmp.set('v.orderIdValue', orderParamValue);
        }

        return isParamInsideURI;
    }
...