It keeps downloading file instead of displaying the file

[chipoyu97]

Hi there, a newbie here. I am looking for help as I am currently learning how to use php. Yesterday, I created a new html file and try to open the atom-live-server. Then, it worked and displayed the page. After that, I used the same page (port3000) to launch my another tutorial php file. The safari popped out a message to ask me "would you like to allow the page to download the file?". I clicked yes, and it turned into a bug that kept downloading the file, instead of displaying the file that I would like to use. However, if I clicked the original file (the html file), it works. Could anyone help me. I appreciate it a lot.

[chipoyu97]

https://youtu.be/FgVlF1-NcnI
to help you better understanding, I have uploaded a video to illustrate. Thanks for ur help.

[chipoyu97]

I guess it works, but something happened.