Api - creating post on behalf of customer doesn't work properly

Hello. When I want to create post in behalf of customer, it is added on behalf of my name, not customer name. This is my code:
$responsePost = Http::withHeaders([
'Authorization' => 'Bearer '.env('PR_API')
])->post('https://productroad.com/api/v1/posts/create/', [
'board' => $data['board'],
'title' => $data['title'],
'content' => $data['content'],
'email' => $email,
'full_name' => $fullName
]);