How to send a message via url with inline buttons

This would be the url you are looking for:

https://api.telegram.org/bot[TOKEN]/sendMessage?chat_id=[CHAT_ID]&text=[TEXT]&reply_markup={"inline_keyboard": [[{"text": "hi", "callback_data": "hi"}]]}

You can pass a JSON toreply_markup field. Here this our JSON:

{
  "inline_keyboard": [
    [
      {
        "text": "hi",
        "callback_data": "hi"
      }
    ]
  ]
}

I suggest you use an API library to communicate with Telegram. Using bare urls has its own challenges, like sometimes you should url encode your JSON to avoid errors in URL.

For example this is the url-encoded version of above JSON:

%7B%22inline_keyboard%22%3A%20%5B%5B%7B%22text%22%3A%20%22hi%22%2C%20%22callback_data%22%3A%20%22hi%22%7D%5D%5D%7D