You are confusing two different modes of operation - parsing command line arguments and prompting for user input then processing it.

@ARGV is initialized with the arguments passed on the command line when your script is executed. You do not need to prompt for the values - it is too late for the user to change the values in any case.

The prompt/process mode uses STDOUT (in exactly the way your code demonstrates) to prompt the user for input at run time. Your code should then use <STDIN> to get a line of response from the user. For example you could write:

print STDOUT "enter the name of the beacon\n";
my $beacon = <STDIN>;
...
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You may then want to chomp $beacon to remove the trailing line end sequence and possibly validate the user provided value in some fashion.