In the US, people will sometimes say; Thank you all for coming or for your participation, and then you simply stand up. This signals that it's over.

Lawyers like to do this. It's a power play to let everyone know who's in charge. It's like a gorilla beating his chest.

You can say: "The meeting is now closed."

Hi Shenjja, I teach how to participate in and vote during a meeting, as well as how to communicate with colleagues. If you'd like to know more you can drop me a mail. Regards.

I suggest expressions that start:

It's time to...

Wrap up the meeting

(Prepare to finish the meeting, deal with the final points)

... Finish the meeting. Thank you all for coming.

Perhaps one of these:

The meeting has concluded.

The meeting has ended.