Connect arduino esp8266 dht11 wemos d1

sensor.ino

#include <DHT.h>
#include <ESP8266WiFi.h>

String apiKey = "thingspeak api key";
const char* ssid = "ssid name";
const char* password = "ssid password";
const char* server = "api.thingspeak.com";

#define DHTPIN D2
#define DHTTYPE DHT11 
 
DHT dht(DHTPIN, DHTTYPE);
WiFiClient client;
 
void setup() 
{
    Serial.begin(115200);
    delay(10);
    dht.begin();
    
    WiFi.begin(ssid, password);
    
    Serial.println();
    Serial.println();
    Serial.print("Connecting to ");
    Serial.println(ssid);
    
    WiFi.begin(ssid, password);
    
    while (WiFi.status() != WL_CONNECTED) 
    {
    delay(500);
    Serial.print(".");
    }
    Serial.println("");
    Serial.println("WiFi connected");
}
 
void loop() 
{
 
    float h = dht.readHumidity();
    float t = dht.readTemperature();
    if (isnan(h) || isnan(t)) 
    {
    Serial.println("Failed to read from DHT sensor!");
    return;
    }
    
    if (client.connect(server,80)) {
        String postStr = apiKey;
        postStr +="&field1=";
        postStr += String(t);
        postStr +="&field2=";
        postStr += String(h);
        postStr += "\r\n\r\n";
        
        client.print("POST /update HTTP/1.1\n");
        client.print("Host: api.thingspeak.com\n");
        client.print("Connection: close\n");
        client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
        client.print("Content-Type: application/x-www-form-urlencoded\n");
        client.print("Content-Length: ");
        client.print(postStr.length());
        client.print("\n\n");
        client.print(postStr);
        
        Serial.print("Temperature: ");
        Serial.print(t);
        Serial.print(" degrees Celsius Humidity: ");
        Serial.print(h);
        Serial.println("Sending data to Thingspeak");
    }
    client.stop();
    
    Serial.println("Waiting 20 secs");
    delay(20000);
}