use LWP::UserAgent::Proxified;

my $ua = LWP::UserAgent::Proxified->new(
  proxylist => [
      ['http', 'https'] => 'http://10.0.0.1:1080',
      ['http', 'https'] => 'http://10.0.0.2:1080'
  ],
  proxyrand => 1, # choose random proxy for each request
# other lwp options goes here
);