How to get access rights to VK API messages when authorizing on the site?

Question

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I have authorization on the site through vk api. Via vk application (type: website) How to get access rights: messages, now if I add in scope
scope: ['messages'],
Then I have an error from vk :

standalone applications should use blank.html as redirect_uri to access messages

Answer 1

Messages can only be accessed by the standalone application, not the
VK API website
Implicit Flow

If you are developing a web application and want to work with the API from Javascript, you must specify the address of the page on your site in the redirect_uri. For security purposes, this address must also be specified in the settings of your application (fields "Site Address", "Base Domain" and "Trusted Redirect URI"). Please note that you will not be able to work with methods that are marked as available only for Standalone applications.