Cors

Front:
headers: {
                'Content-Type': 'application/json',
                'Accept': '*/*',
               'Authorization' : '',
                'Origin': 'http://localhost:3000',
                'Mode': 'cors'
            },
              
Back: 
builder.Services.AddPersistence(builder.Configuration);
var MyAllowSpecificOrigins = "_myAllowSpecificOrigins";

builder.Services.AddCors(options =>
{
    options.AddPolicy(MyAllowSpecificOrigins,
        policy =>
        {
            //mettre le front 
            policy.WithOrigins("http://localhost:3000")
                .AllowAnyHeader()
                .AllowAnyMethod();
        });
});