for i in 470.{771..1000}
  do 
  p3-genome-fasta --contig ${i} > out_${i}.contig
  done

What do you mean by "a folder"? What does this command produce?

Not sure if your output need to be renamed, but here is in Perl:

#!/usr/bin/perl
use strict;
use warnings;

while (<>) {
    chomp;
    my $id = $_;
    system("p3-genome-fasta --contig $id > out_$id.contig")
}

so you can run as perl run.pl < file_with_ids.txt