hiii i want to know this HDMI is work for iphone 12??

Yes, you can connect the iPhone to a Tv using an HDMi port on the TV. Not sure what it has to do with a Mac.

Since the iPhone does not have an HDMI port, you need an adapter for that: link-> Lightning Digital AV Adapter - Lightning to HDMI - Apple

Work in what way? The HDMI port on a Mac is for video output. It has nothing to do with an iPhone.

If you are wanting to know wether it will let you see the iPhone's screen on your Mac, then no, it won't, as stated its an output only port.

What exactly are you trying to accomplish?