У вашего броузера проблема в совместимости с HTML5
Frame assembly tutorial for Quadruped Robot
has a longer body for walking and maneuvering stability...
You can download the 3D object on :
https://www.thingiverse.com/thing:3122758
https://www.myminifactory.com/object/3d-print-75550
and here is the complete tutorial :
https://www.instructables.com/id/ESP8266-WIFI-AP-Controlled-Quadruped-Robot/
PS:Sorry for some typo on caption