Q: my iphone can't detect my Macbook while my mac is able to drop files to my phone

Look through this and make sure everything is set up and compatible.

Not all Macs can use Airdrop

Use AirDrop to send content from your Mac - Apple Support

Note that if your iPhone isn't in the contacts list of your Mac, the Mac will not show up on the iPhone unless you set the Mac to be discoverable by everyone, as seen in the picture under "Share Items" in that article.