i will try my best to explain my question.

currently i am working with a requirement in which user can login with the local db user and can login with the Azure AD, with the local db user i am creating custom token by using below code.

public static string GenerateJwtToken(string userId, string userName, string secret)
    {
        var tokenHandler = new JwtSecurityTokenHandler();
        var key = Encoding.ASCII.GetBytes(secret);

        var tokenDescriptor = new SecurityTokenDescriptor
        {
            Subject = new ClaimsIdentity(new[]
            {
                new Claim(ClaimTypes.NameIdentifier, userId),
                new Claim(ClaimTypes.Name, userName)
            }),
            Expires = DateTime.UtcNow.AddDays(7),
            SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
        };
        var token = tokenHandler.CreateToken(tokenDescriptor);
        var encryptedToken = tokenHandler.WriteToken(token);

        return encryptedToken;
    }

and validating the token with the below code.

        public static IServiceCollection AddJwtAuthentication(this IServiceCollection services, IdentityAppSettings appSettings)
    {
        var key = Encoding.ASCII.GetBytes(appSettings.SecretKey);

        services
            .AddAuthentication(x =>
            {
                x.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                x.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            })
            .AddJwtBearer(x =>
            {
                x.RequireHttpsMetadata = false;
                x.SaveToken = true;
                x.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidateIssuerSigningKey = false,
                    IssuerSigningKey = new SymmetricSecurityKey(key),
                    ValidateIssuer = false,
                    ValidateAudience = false
                };
            });
        return services;
    }

and for Azure AD i am using the below code in the statup.cs class

services.AddMicrosoftIdentityWebApiAuthentication(Configuration, "AzureAd");

appsettings.json

  "AzureAd": {
"Instance": "https://login.microsoftonline.com/",
"TenantId": "11121313213213132132",
"ClientId": "46853216534163",
"Audience": "api://11121313213213132132"

},

but its throwing below error "Scheme already exists: Bearer"

now my question is how can we use multiple token validator together, and how can we check the token is valid from one so we should not check in another validator.