Sample Code:

Component:

<aura:component implements="force:appHostable"
                controller="AccountListController">
    
    <aura:attribute type="Account[]" name="acctList"/>
    <aura:attribute name="mycolumns" type="List"/>
    
    <aura:handler name="init" value="{!this}" action="{!c.init}"/>
    
    <div style="height: 300px">
        <lightning:datatable data="{! v.acctList }" 
                             columns="{! v.mycolumns }" 
                             keyField="Id"
                             hideCheckboxColumn="false"
                             enableInfiniteLoading="true"
                             onloadmore="{! c.loadMoreData }"
                             onrowselection="{! c.updateSelectedText }"
                             loadMoreOffset="5"/>
    </div>
    
</aura:component>

Controller:

({
    
    init : function(component, event, helper) {
        
        console.log( 'Inside Init Method' );
        component.set('v.mycolumns', [
            {label: 'Account Name', fieldName: 'linkName', type: 'url', 
            typeAttributes: {label: { fieldName: 'Name' }, target: '_blank'}},
            {label: 'Industry', fieldName: 'Industry', type: 'text'},
            {label: 'Type', fieldName: 'Type', type: 'Text'}
        ]);
        
        helper.fetchAccounts( component, event, 0 );
        
    },
    
    loadMoreData : function( component, event, helper ) {
        
        event.getSource().set("v.isLoading", true);        
        component.set('v.loadMoreStatus', 'Loading');
        helper.fetchAccounts(component, event, component.get('v.acctList').length);
        
    },
    
    updateSelectedText: function ( component, event, helper ) {
        
        console.log( 'Inside updateSelectedText Method' );
        let selectedRows = event.getParam( 'selectedRows' );
        console.log( selectedRows.length );
        
    }

})

Helper:

({
    
 fetchAccounts : function(component, event, offSetCount) {
  
        var action = component.get("c.fetchAccts");
        action.setParams({
            
            "intOffSet" : offSetCount
            
        });
        
        action.setCallback(this, function(response) {
            
            var state = response.getState();
            if (state === "SUCCESS") {
                var records = response.getReturnValue();
                records.forEach(function(record){
                    record.linkName = '/'+record.Id;
                });
                var currentData = component.get('v.acctList');                
                component.set("v.acctList", currentData.concat(records));
            }
         event.getSource().set("v.isLoading", false);
            
        });
        
        $A.enqueueAction(action);
        
 }
    
})

Apex Class:

public class AccountListController {
    
    @AuraEnabled
    public static List < Account > fetchAccts( Integer intOffSet ) {
        
        return [ 
            SELECT Id, Name, Industry, Type 
            FROM Account 
            LIMIT 5 OFFSET : Integer.valueOf( intOffSet ) 
        ];
        
    }
    
}

Output: