Why do you have a * asterisk under your Mac with a filename?

This * is only the LS command display, indicating that there is executable permission, the actual file name without the * number.

Ls-f
The executable file name will be added with the * number.

Displays information about one or more files.
ls [options] [file-list]

Parameters
By default, LS lists the file's information in alphabetical order by filename, file-list can be any file or directory
When file-list contains multiple directories, LS displays the name of the directory and does not display subdirectories and sub-files
When File-list is a normal file, LS displays information about the file

Options
-a displays the list of all file names, including hidden files (filenames begin with a period)
-A is similar to-a but not listed. And.. Catalog items
-l lists more information for each file
-m displays file names separated by commas, and the width of the file list is the same as the width of the screen
-H Displays the size of the file from K (Kbytes), M (MBytes), and G (gigabytes) to select the appropriate units
-r lists the directory hierarchy in reverse order
-R recursively lists the contents of subdirectories
-T displays the file in the order of the last modified time
-U display files in the order of last access time
-X displays a list of files by row (by default, by column)
-X displays files in the order of file extensions, files with no extension are listed first
-11 lines showing a file
-D displays only the directory name
-F This option displays a slash (/) after each directory, an asterisk (*) after each executable file, and a symbol after each symbol link @

Why do you have a * asterisk under your Mac with a filename?