Add Custom lookup on EP

The trick is to override datasetLookup() on Dataset > data source > field > methods. You will not find this method in the list of override methods so just create this as new method.
the table which we are using for lookup should be in the Dataset

public void dataSetLookup(SysDataSetLookup sysDataSetLookup)
{
    List list = new List(Types::String);

    Query query = new Query();

    QueryBuildDataSource    queryBuildDataSource;

    QueryBuildRange qbr;

    // Add the table to the query.

    queryBuildDataSource  = query.addDataSource(tableNum(HcmWorker));

    //add the range

    qbr = queryBuildDataSource.addRange( fieldnum(HcmWorker, PersonnelNumber));

   // qbr.value(DirPersonUser::currentWorkerPersonnelNumber());

   // qbr.status(RangeStatus::Locked);

     // Specify the fields to use for the lookup.

    list.addEnd(fieldStr(HcmWorker,PersonnelNumber));

    list.addEnd(fieldStr(HcmWorker,Name()));


     sysDataSetLookup.parmLookupFields(list);

     // Specify the field that is returned from the lookup.

    sysDataSetLookup.parmSelectField('PersonnelNumber');

     // Pass the query to the SysDataSetLookup so that the query is used.

    sysDataSetLookup.parmQuery(query);
 
}

Table browser URL in D365FO

https://usnconeboxax1aos.cloud.onebox.dynamics.com/?mi=SysTableBrowser&prt=initial&limitednav=false&cmp=usmf&tablename=CustTable

Unit conversions using X++ , Standard and Intra-class conversions in AX

Standard conversion

RefRecId unitOfMeasureFromRecId = UnitOfMeasure::findBySymbol(inventTable.salesUnitId()).RecId;
RefRecId unitOfMeasureToRecId = UnitOfMeasure::findBySymbol(salesLine.SalesUnit).RecId;

real defaultUnitConvertedQty =  UnitOfMeasureConverter::convert(abs(inventTrans.Qty),
                                                                           unitOfMeasureFromRecId,//from
                                                                           unitOfMeasureToRecId,//To
                                                                           NoYes::No);

Intra-class conversion

real unitConvertedQty = EcoResProductUnitConverter::convertGivenUnitSymbolsForReleasedProduct(inventTable.ItemId,
                                                                                                         salesLine.InventDimId,
                                                                                                         abs(inventTrans.Qty),
                                                                                                         inventTable.salesUnitId(),//from
                                                                                                         salesLine.SalesUnit,//To
                                                                                                         NoYes::No);

Show Information in Action center in D365 finance and operations instead of using infolog

class RunnableClass1
{
    /// <summary>
    /// Runs the class with the specified arguments.
    /// </summary>
    /// <param name = "_args">The specified arguments.</param>
    public static void main(Args _args)
    {
        SystemNotificationDataContract notification = new SystemNotificationDataContract();
        notification.Users().value(1, curUserId());
        notification.Title("@ApplicationPlatform:ExportToExcel_ActionCenterCompletedTitle");
        notification.RuleId('ExcelStaticExport');
        str formCaption = "Your text";
        notification.Severity(SystemNotificationSeverity::Warning);
                         notification.Message(strFmt("@ApplicationPlatform:ExportToExcel_ActionCenterCompletedMessage", formCaption));

        // Set the expiration an hour less than the expiration of the blob to avoid a condition where the blob expires before the message
        notification.ExpirationDateTime(DateTimeUtil::addHours(DateTimeUtil::utcNow(), 48));
        SystemNotificationsManager::AddNotification(notification);
    }

}