Sending notifications to mobile devices using firebase Firebase Admin

I'm trying to send notifications to mobile devices using firebase admin sdk with asp.net mvc... But I'm stuck a certain request limit. Is there any way to get around this limit? I share some snippets of my code below.

var path = HttpContext.Current.Server.MapPath("~/assd.json");
var path = HttpContext.Current.Server.MapPath("~/assd.json");
FirebaseApp.Create(new AppOptions()
{
Credential = GoogleCredential.FromFile(path),
ProjectId = "*********",
});
var message = new MulticastMessage
{
Data = new Dictionary<string, string>()
{
{ "type", type },
{ "typeValue", typeValue },
{ "isSound", isSound.ToString()},
{ "title", title},
{ "body", spot },
},
Apns = new ApnsConfig()
{
Headers = new Dictionary<string, string>()
{
{ "apns-priority", "10" },
},
Aps = new Aps()
{
Alert = new ApsAlert()
{
Title = title,
Body = spot,
},
Badge = 1,
},
},
Tokens = tokens,
};
var response =FirebaseMessaging.DefaultInstance.SendMulticastAsync(message).Result;
if (response.FailureCount > 0)
{
var failedTokens = new List<string>();
for (var i = 0; i < response.Responses.Count; i++)
{
if (!response.Responses[i].IsSuccess)
{
failedTokens.Add(tokens[i]);
listLog.Add(tokens[i]);
}
}
}

I also try to use the topic system, but it also has a limit.

Thank you.. Sofware Developer