How to fix a request to the VK API and get rid of the server error?

Question

API

The goal is to send messages on behalf of the group to the VKontakte group dialog
I make a request

https://api.vk.com/method/messages.send?chat_id=99&random_id=20607840408&message=Тестовое сообщение&access_token=ключ_доступа_для_группы&v=5.95

And I get a response:

"Internal server error"

- the first drawing.
The token, of course, is not the same as written here, but received in a group, as in the second figure.
Bot options as in the third figure. And of course the bot
was added to conversation 99 with the url https://vk.com/im?peers=ХХХХХХХХ&sel=c99 (99), message - and message gets into the desired dialog. And the https request, as I wrote above, gives an internal server error. Can't figure out how to deal with this.

Answer 1

Found the answer at https://lolzteam.net/threads/555934/

5. In the first field, you need to insert the id of the conversation, but not yours, but the bot, that is, in order, they were invited to the first conversation - id 1 to the second - id 2, etc.