IDE Upload error - Uploading from IDE to UNO & ESP-01S

Uploading RemoteXY example Arduino UNO + external ESP8266 as WiFi access point

Here is the IDE error message

Sketch uses 272195 bytes (26%) of program storage space. Maximum is 1044464 bytes.
Global variables use 28504 bytes (34%) of dynamic memory, leaving 53416 bytes for local variables. Maximum is 81920 bytes.
"/home/nor/.arduino15/packages/esp8266/tools/python3/3.7.2-post1/python3" -I "/home/nor/.arduino15/packages/esp8266/hardware/esp8266/3.1.1/tools/upload.py" --chip esp8266 --port "/dev/ttyACM0" --baud "115200" ""  --before default_reset --after hard_reset write_flash 0x0 "/tmp/arduino-sketch-8CFFA33AE14007AEE1970A3D179AB8CC/project.ino.bin"
esptool.py v3.0
Serial port /dev/ttyACM0
Connecting........_____....._____....._____....._____....._____....._____....._____

A fatal esptool.py error occurred: Failed to connect to ESP8266: Timed out waiting for packet header

Board and modules wired as per example, pin 1 2 (RT TX) disconnected as per instructions.  IDE 2.0.3 running on Linux Mint 21.1 Mate

Don't know how to get around the problem. 
Git HUB also has the error https://github.com/espressif/esptool/issues/490   They talk about pin setting etc.  Don't understand what they are referring to. 

HELP !

will try it on Win10 as I have a dual boot system. I have tried other UNO boards, NO JOY!

The ESP module is a Stemedu ESP8266 ESP-01S WiFi Serial Transceiver Module with 4MB Flash DIP-8 3-6V from Amazon.CA