无法从json响应中获取访问令牌

{
    "access_token": "your_access_token_here",
    "token_type": "Bearer",
    "expires_in": 3600
}

fetch('https://example.com/api/token')
    .then(response => response.json())
    .then(data => {
        if (data.access_token) {
            console.log('Access Token:', data.access_token);
        } else {
            console.error('Access Token not found in response');
        }
    })
    .catch(error => {
        console.error('Error fetching access token:', error);
    });

fetch('https://example.com/api/token')
    .then(response => {
        if (!response.ok) {
            throw new Error('Server error: ' + response.status);
        }
        return response.json();
    })
    .then(data => {
        console.log('Access Token:', data.access_token);
    })
    .catch(error => {
        console.error('Error:', error);
    });

fetch('https://example.com/api/token', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json',
        'Authorization': 'Basic ' + btoa('client_id:client_secret')
    },
    body: JSON.stringify({
        grant_type: 'client_credentials'
    })
})
.then(response => {
    if (!response.ok) {
        throw new Error('Server error: ' + response.status);
    }
    return response.json();
})
.then(data => {
    if (data.access_token) {
        console.log('Access Token:', data.access_token);
    } else {
        console.error('Access Token not found in response');
    }
})
.catch(error => {
    console.error('Error fetching access token:', error);
});