Is it possible to send messages to Vk users through a php site?

Question

PHP

The question is the following. Is it possible to send a message to VK users from the site.
Here is an article , but when I try to send a message from the site, I get an error
{"error":{"error_code":17,"error_msg":"Validation required: please open redirect_uri in browser 1085252950","request_params":[{"key" :"oauth","value":"1"},{"key":"method","value":"messages.send"},{"key":"user_id","value":"63440239" },{"key":"message","value":"3351"},{"key":"v","value":"5.37"}],"redirect_uri":"https:\/\/ m.vk.com\/login?act=security_check&

Answer 1

Came from a server in another country, most likely. Asks to open url to confirm authorization.