In general, no person or organization can charge you a fee to help you file your initial application for benefits. But they may charge you for unusual expenses.
do you think a claims agent or attorney charged you a fee that is too high?
do not
How do I find an accredited representative or a VSO?
You can find an accredited representative or a VSO in 1 to 2 ways:  Go to eBenefits to find a local representative that includes a recognized VSO, attorney, or claims agent by state / territory, zip code, or organization name.
What are VSOs and what do they do?
VSOs work on behalf of veterans and service members, as well as their dependents and survivors
and what else can these professionals do?
These trained professionals can also: Help gather supporting documents, such as a doctor's report or medical test results.   file a claim or appeal on your behalf
ok and how can I do if I want to make an appeal but I can't be present?