cross origin issue :No 'Access-Control-Allow-Origin' header is present on the requested resource. · Issue #370 · miguelgrinberg/Flask-SocketIO · GitHub
![javascript - No 'Access-Control-Allow-Origin' header is present on the requested resource (flask - python - js) - Stack Overflow en español javascript - No 'Access-Control-Allow-Origin' header is present on the requested resource (flask - python - js) - Stack Overflow en español](https://i.stack.imgur.com/DYnPV.png)
javascript - No 'Access-Control-Allow-Origin' header is present on the requested resource (flask - python - js) - Stack Overflow en español
![Access to XMLHttpRequest has been blocked by CORS policy: No 'Access-Control -Allow-Origin' header is present on the requested resource. · Issue #1009 · miguelgrinberg/Flask-SocketIO · GitHub Access to XMLHttpRequest has been blocked by CORS policy: No 'Access-Control -Allow-Origin' header is present on the requested resource. · Issue #1009 · miguelgrinberg/Flask-SocketIO · GitHub](https://user-images.githubusercontent.com/2340878/60219367-036afb00-9827-11e9-9507-7ad8ec30f456.png)
Access to XMLHttpRequest has been blocked by CORS policy: No 'Access-Control -Allow-Origin' header is present on the requested resource. · Issue #1009 · miguelgrinberg/Flask-SocketIO · GitHub
![Definitive guide to solve CORS error, Access-Control-Allow-Origin in Python Flask APIs - DEV Community Definitive guide to solve CORS error, Access-Control-Allow-Origin in Python Flask APIs - DEV Community](https://dev.to/social_previews/article/472901.png)
Definitive guide to solve CORS error, Access-Control-Allow-Origin in Python Flask APIs - DEV Community
![python - Not getting Access-Control-Allow-Headers and Access-Control-Max-Age with flask-cors - Stack Overflow python - Not getting Access-Control-Allow-Headers and Access-Control-Max-Age with flask-cors - Stack Overflow](https://i.stack.imgur.com/v54ox.png)