Sharepoint Caml Query

c# Connect to Sharepoint with ClientContext appId and certificat ThumbPrint

using Microsoft.Identity.Client;
using Microsoft.SharePoint.Client;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;

namespace MY.PNP.Powershell.EXT.CSOM
{
    public class CsomContext : IDisposable
    {
        public ClientContext _clientContext;
        public ClientRuntimeContext _context;

        private async Task GetAccessToken(string tenantName, string clientId, string thumbprint)
        {
            var certificate = GetCert(thumbprint);
            var authority = $"https://login.microsoftonline.com/{tenantName}.onmicrosoft.com/";
            var azureApp = ConfidentialClientApplicationBuilder.Create(clientId)
                .WithAuthority(authority)
                .WithCertificate(certificate)
                .Build();

            var scopes = new string[] { $"https://{tenantName}.sharepoint.com/.default" };
            var authResult = await azureApp.AcquireTokenForClient(scopes).ExecuteAsync();
            return authResult.AccessToken;
        }

        public async Task CallClientObjectModel(string tenantName, string url, string clientId, string thumbprint)
        {
            var token = await GetAccessToken(tenantName, clientId, thumbprint);
            var siteUrl = url;//;$"https://{tenantName}.sharepoint.com";

            var context = new ClientContext(siteUrl);

            context.ExecutingWebRequest += (s, e) =>
            {
                e.WebRequestExecutor.RequestHeaders["Authorization"] =
                    "Bearer " + token;
            };

            var web = context.Web;
            context.Load(web);
            context.ExecuteQuery();
            Console.WriteLine(web.Title);
            Console.WriteLine(web.Url);
            _context = web.Context;
            _clientContext = context;
        }

        private X509Certificate2 GetCert(string thumbprint)
        {
            X509Store certStore = new X509Store(StoreName.My, StoreLocation.CurrentUser);
            certStore.Open(OpenFlags.ReadOnly);
            X509Certificate2Collection certCollection = certStore.Certificates.Find(
                                       X509FindType.FindByThumbprint,
                                         // Replace below with your cert's thumbprint
                                         thumbprint,
                                       false);
            X509Certificate2 cert = null;
            // Get the first cert with the thumbprint
            if (certCollection.Count > 0)
            {
                cert = certCollection[0];
                // Use certificate
                Console.WriteLine(cert.FriendlyName);
            }
            certStore.Close();
            return cert;
        }

        public void Dispose()
        {
            if (_context != null)
                _context.Dispose();
            if (_clientContext != null)
                _clientContext.Dispose();
        }
    }
}

Add custom WebPart On Modern Page Powershell

List your webpart with :

$page = Get-PnPPage -Identity "aTestDisp2.aspx"

$page.AvailablePageComponents() select your webpart by name or guid

param([string]$siteUrl="https://myyTenant.sharepoint.com/sites/muSite", [string]$pageName="aTestDisp2", [string]$webPartName="Test - Display Item")
clear
Connect-PnPOnline -Url $siteUrl -UseWebLogin
#set your wenpart properties
$wpProps = @{webUrl="https://myyTenantsharepoint.com/sites/muSite"
            listId="b4d5f780-bd74-4cd5-b051-fed423e43125"
            field="Title"
            itemId="1"}

#get the page
$page = Get-PnPPage -Identity $pageName

# get the target webpart
$wp = $page.AvailablePageComponents() | Where-Object {$_.Name -eq $webPartName }
if($wp -eq $null)
{
    Write-Host "webpart '$($webPartName)' not found " -ForegroundColor:Red
}
#Add webpart with default user, to column 1 in section 1
Add-PnPPageWebPart -Page $pageName -Component $wp -Section 1 -Column 1 -WebPartProperties $wpProps
Disconnect-PnPOnline

You can check webpart properties, in result