Error 403 when calling APIs of Office365 with authentication of AzureAD

I'm making a web application to call Office365 REST API, and is using the authentication function of Azure AD. I am not having any progress since last week, and we suddenly got this error:

statuscode: 403,
body: '{"error":{"code":"ErrorAccessDenied","message":"Access is denied. Check credentials and try again."}}

Here is the request that I sent

var request = {
    url: url,
    method: method,
    json: (method === constants.GET || method === constants.DELETE) ? null : resource,
    headers: {
        'Authorization': credentials.tokenType + ' ' + credentials.accessToken,
        'User-Agent': clientId,
        'Accept' : 'application/json'
}

Could anyone explain how to fix this?