The problem of using the DB First method in .NET Core 6 using Oracle

Question

I have an application in asp .net core mvc 6 using oracle 11g database. I am using database first approach, when I scaffoled , I get this error:

"ThreadID:1   (ERROR)   OracleDatabaseModelFactory.Create() :  Oracle.ManagedDataAccess.Client.OracleException (0x80004005): ORA-12154: TNS:could not resolve the connect identifier specified
     ---> OracleInternal.Network.NetworkException (0x00002F7A): ORA-12154: TNS:could not resolve the connect identifier specified
       at OracleInternal.Network.AddressResolution..ctor(String TNSAlias, SqlNetOraConfig SNOConfig, Hashtable ObTnsHT, Hashtable ObLdpHT, String instanceName, ConnectionOption CO, String ShardingKeyB64, String SuperShardingKeyB64, String ServerIs)
       at OracleInternal.Network.OracleCommunication.Resolve(String tnsAlias, ConnectionOption& CO)
       at OracleInternal.ConnectionPool.PoolManager`3.ResolveTnsAlias(ConnectionString cs, Object OC)
       at OracleInternal.ServiceObjects.OracleConnectionImpl.Connect(ConnectionString cs, Boolean bOpenEndUserSession, OracleConnection connRefForCriteria, String instanceName)
       at OracleInternal.ConnectionPool.PoolManager`3.Get(ConnectionString csWithDiffOrNewPwd, Boolean bGetForApp, OracleConnection connRefForCriteria, String affinityInstanceName, Boolean bForceMatch)
       at OracleInternal.ConnectionPool.OraclePoolManager.Get(ConnectionString csWithNewPassword, Boolean bGetForApp, OracleConnection connRefForCriteria, String affinityInstanceName, Boolean bForceMatch)
       at OracleInternal.ConnectionPool.OracleConnectionDispenser`3.Get(ConnectionString cs, PM conPM, ConnectionString pmCS, SecureString securedPassword, SecureString securedProxyPassword, OracleConnection connRefForCriteria)
       at Oracle.ManagedDataAccess.Client.OracleConnection.Open()
       at Oracle.EntityFrameworkCore.Scaffolding.Internal.OracleDatabaseModelFactory.Create(DbConnection connection, IEnumerable`1 tables, IEnumerable`1 schemas)"

this is my connectionstring in appsetting.json file:

"ConnectionStrings": {
 "MESWebAppConnectionString": "User Id=msdb;Password=1234;Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=10.100.8.187)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MB3)))"
    
}

program.cs:

builder.Services.AddDbContext<MESWebAppContext>(options =>
{
    options.UseOracle(builder.Configuration.GetConnectionString("MESWebAppConnectionString"));

});

scaffold command:

Scaffold-DbContext "User Id=msdb;Password=1234;Data Source=MB3;" Oracle.EntityFrameworkCore -OutputDir Model -Tables customer,student

I don't Know why this error is coming while scaffolding.

How can I solve it?