How to get content from private bitbucket repository using key:secret pair?

Question

Bitbucket

In general, there is a private repository, there is an OAuth user, the task is to get the content of a file from a private repository, the OAuth user has read access to projects.
Request api https://developer.atlassian.com/bitbucket/api/2/re...
Request code

if ($curl = curl_init())
{
    curl_setopt_array($curl, array(
        CURLOPT_URL => <API_PATH>,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_USERPWD, sprintf("%s:%s", self::CLIENT_ID, self::SECRET)
    ));
    
    $response = curl_exec($curl);
    curl_close($curl);
    echo $response;
}

output error

Access denied. You must have write or admin access.

How to be?