How to delete all exif of DNG?

Or one can use ExifTool, which supports a wide range of file formats and metadata properties - including read/write for DNG:

https://exiftool.org/#supported

For only EXIF (camera) related data:

exiftool -exif:all= 'path to/file/or folder'

For all metadata, but not the ICC profile:

exiftool -all= -CommonIFD0= --icc_profile:all 'path to/file/or folder'

Note: Windows OS would use " double straight quotes. These commands will dupe the input file and rename the original file as a backup. To overwrite the originals without a backup, add the following argument with the others:

-overwrite_original

Note: Always work on copies while you are learning!

I have not used this, but it seems pretty straightforward. Plus, you can do this in bulk

https://apps.apple.com/app/id784466108

This leads you to both a Mac and a PC version