How can I fix this error of ESP8266: "warning: espcomm_sync failed error: espcomm_open failed error: espcomm_upload_mem failed"?

Question

I'm doing a project with ESP8266-01. This is how I connected it with PL2303:

PL2303 ---> ESP8266
3.3V ---> VCC, CH_PD
TXD ---> RX
RXD ---> TX
GND ---> GPIO0, GND

Next, I opened Arduino IDE (version 1.8.19) and added this code to my sketch (I'm using esp8266 library version 2.1.0):

#include <ESP8266WiFi.h>         

const char *ssid = "ESP AP";     
const char *password = "12345";     

void setup() {
Serial.begin(115200);            

WiFi.softAP(ssid, password);     
Serial.print("Access Point: ");
Serial.print(ssid);
Serial.println(" started");

Serial.print("IP address: ");
Serial.println(WiFi.softAPIP()); 
}

void loop() {}

These are my selections on the Tool tab:
Board: "Generic ESP8266 Module"
Upload Speed: "115200"
CPU Frequency: "80 MHz"
Flash Size: "512K(64K SPIFFS)"
Flash Mode: "DIO"
Flash Frequency: "40 MHz"
Upload Using: "Serial"
Reset Method: "ck"
Debug port: "Disabled"
Debug Level: "None"
Port: "COM13" (my PL2303 COM port)
Programmer: No programmers available for this board

Then I connected my PL2303 to my computer (Windows 10) and hit Upload. It compiled just fine, but I got this logged on my console:

Sketch uses 233067 bytes (53%) of program storage space. Maximum is 434160 bytes.

Global variables use 31920 bytes (38%) of dynamic memory, leaving 50000 bytes for local 
variables. 
Maximum is 81920 bytes.

warning: espcomm_sync failed

error: espcomm_open failed

error: espcomm_upload_mem failed

error: espcomm_upload_mem failed

What should I do now to fix this error?

Update: I switched ESP8266v1 with NodeMCU-01 CH340. I'm still using the above sketch to upload to my board. It uploads without error, but I can't see any results like the wifi network created by that sketch (I mean the one with the SSID "ESP AP" but I only see a weird wifi network named "FaryLink_(with a few numbers)" and I think that maybe the wifi network of NodeMCU but that doesn't what I really want) or stuff printed on Serial Monitor. On the Tool tab, I set things up like this (esp8266 library version 3.0.2, Arduino version 1.8.18):
Board:"NodeMCU 1.0 (ESP-12E Module)"
Builtin Led:"2"
Upload Speed:"115200"
CPU Frequency:"80 MHz"
Flash Size:"4MB(FS:2MB OTA:~1019)"
Debug port:"Serial"
Debug Level:"None"
IwIP Variant:"v2 Lower Memory"
VTables:"Flash"
C++ Exceptions:"Disabled (new aborts on oom)"
Stack Protection:"Disabled"
Erase Flash:"Only Sketch"
SSL Support:"All SSL ciphers (most compatible)"
MMU:"32KB cache + 32KB IRAM (balanced)"
Non-32-Bit Access:"Use pgm_read macros for IRAM/PROGMEM"
Port:"COM14"
Anyone can help me solving my problem?

Answer 1

Finally, I decided to change the Arduino version to 1.8.8, esp library version 2.5.0; I've tested with another the sketch and it WORKED!!! I will share my selection on the Tool tab, hope it'll help someone:
Board:"NodeMCU 1.0 (ESP-12E Module)"
Upload Speed:"115200"
CPU Frequency:"80 MHz"
Flash Size:"4MB(3M SPIFFS)"
Debug port:"Serial"
Debug Level:"None"
IwIP Variant:"v2 Lower Memory"
VTables:"Flash"
Exceptions:"Disabled"
Erase Flash:"Only Sketch"
Port:"COM14"
Programmer:"Arduino as ISP"
The sketch I used:

const char* ssid     = "name_of_wifi";         // The SSID (name) of the Wi-Fi 
network you want to connect to
const char* password = "password_of_wifi";     // The password of the Wi-Fi network

void setup() {
  Serial.begin(115200);         // Start the Serial communication to send 
messages to the computer
  delay(10);
  Serial.println('\n');

  WiFi.begin(ssid, password);             // Connect to the network
  Serial.print("Connecting to ");
  Serial.print(ssid); Serial.println(" ...");

  int i = 0;
  while (WiFi.status() != WL_CONNECTED) { // Wait for the Wi-Fi to connect
    delay(1000);
    Serial.print(++i); Serial.print(' ');
  }

  Serial.println('\n');
  Serial.println("Connection established!");  
  Serial.print("IP address:\t");
  Serial.println(WiFi.localIP());         // Send the IP address of the ESP8266 
to the computer
    }

void loop() { }

Answer 2

In the circuit the GPIO0 pin is connected to VCC through a 10 k resistor. The voltage on the reset pin is 1.97V. in normal operation. I removed this resister and connected the GPIO0 pin manually. Normal operation--> GPIO0 not connected Program mode --> GPIO0 to GND--> switch on VCC --> GPIO0 to VCC --> not connected (to normal operation)

I tried it with 5 esp8266 modules which all were functioning properly after this modification and did not before.

I did it with the blink example But when I loaded another program in the arduino, it failed uploading to the esp/ Why? The only difference was the upload speed of the serial monitor.

the arduino file: void setup() { //Serial.begin(115200);

When i commented this lline, the upload to the esp worked. ( //Serial.begin(115200); ) when I uncommented it, ( Serial.begin(115200); ) the upload to the esp failed.

So as soon as the Arduino sketch has a serial begin, the communication to the ESP fails.