How do I permanently delete files from my mac?

You neglected to mention the exact model of this Mac and version of macOS involved. Plus you neglected to mention if this data is on the internal boot drive, or an external drive (need to know type & file system).

If your data is stored on the internal SSD, then there is no way to securely delete the data due to how SSDs work. It doesn't matter though, since the data is gone once that SSD block is taken offline to be reused since the SSD block must be reset by the SSD before it can be re-used. Don't worry about it if the data is stored on the internal SSD.

If the data is stored on a hard drive utilizing the APFS file system, then over writing the file won't work due to how the APFS file system works. However, if the data is stored on a hard drive using MacOS Extended file system, then it is possible to over write the data in the file to destroy it.

Anything that changes how the APFS file system works could cause unexpected data loss.

Highlight the file.

Then press Command+ Option in that order, then press delete.

Using srm can definitely help you permanently delete files from Mac, but just be aware of its drawbacks. It’s a powerful tool, but it comes with some risks of usability and potential issues.

I remember when I first started using Terminal commands to manage files. I'd just read about how srm works, and I thought, "This is going to be great for deleting sensitive stuff!" But I misclicked once, and instead of deleting a document, I accidentally wiped out a project folder. Talk about a freak-out moment! It’s crucial to double-check before hitting Enter.