Getting invalid token id using stripe connect - php

Question

I am using Stripe Connect for stripe integration. In this, we firstly create a managed account under an existing stripe account. Then we charge the customer and the charge is transferred to one account and application fee to the managed account. By creating a managed account, we get the account id associated to it using:
$acc=\Stripe\Account::create(
array(
"country" => "US",
"managed" => true
)
);
Then we charge customer and link two accounts with that charge using application fee concept as follows:
$c_charge = \Stripe\Charge::create(
array(
"amount" => 1000, // amount in cents
"currency" => "usd",
"source" => {TOKEN OF CUSTOMER},
"description" => "Example charge",
"application_fee" => 123 // amount in cents
),
array("stripe_account" => 'acct_15rTMLISz4VN6mw2')
);
In this case since the stripe account with which the application fee is linked has no bank account connected for money transfer, so now we need to link the bank account with the stripe account
Following code is based on it, but it generates an error: Invalid token id
$data=array(
'bank_account'=> $token
);
$pHttp_headers=array(
"Content-Type: application/x-www-form-urlencoded",
"Authorization: Bearer {$stripe['secret_key']}"
);
$ch=curl_init();
curl_setopt($ch,CURLOPT_URL,"https://api.stripe.com/v1/accounts/acct_15rTMLISz4VN6mw2/bank_accounts");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, $pHttp_headers);
//curl_setopt($ch, CURLOPT_USERPWD,$stripe['secret_key']);
$pResult = curl_exec($ch);
curl_close($ch);
$pResult=json_decode($pResult,true);
This is the error I am getting:
Array ( [error] => Array ( [type] => invalid_request_error [message] => Invalid token id: tok_15rlFFHPiBMaAbxH6hwPNcDL [param] => bank_account ) )
Any ideas?