Are there any restrictions on the number of messages that can be received and sent in WhatsApp?
You can send an unlimited number of messages via the Chat API.
At the same time, we do not recommend sending more than 6000 thousand messages per day (no more than 5-10 messages per minute) from one number. This is fraught with possible bans, if you need to send more than 6000 thousand messages, then the solution may be to purchase additional instances.
You can find out how to add and pay for instances here.
You can read our recommendations for working with the service to reduce the likelihood of being banned here.