The mention in a group feature is very cool within WhatsApp groups, and you can easily do this to one or more than one contact at the same time using Ultramsg API.
Parameter values for mention in a WhatsApp group:
1 – to: Group ID.
2- body : The text of the WhatsApp message, in addition to the numbers we want to mention, with the @ symbol before each number.
3-mentions : The number we want to mention, and if it is more than one number, a comma must be placed between the numbers.
Useful Links :