Hello ​@Ridho ,
ManyChat allows external HTTP requests, so if this tool can handle external requests, the integration is theoretically possible.
I visited the website and clicked on the documentation tab, but it didn’t lead to any page, so I couldn’t confirm whether they provide an available API.

Typically, for this type of integration, you would use ManyChat’s external request block to send data to the tool. To send data back to ManyChat, you can use the ManyChat API to populate custom fields and trigger flows.
Here is the ManyChat documentation page, where you can find all available options and usage guidelines:
https://api.manychat.com/swagger#/

i check again to tapsite.ai  , it requires Webhooks URL to send form submission data to external services in real-time.  Is there any simply and free step to integrate Manychat with Webhooks URL?

Manychat does not currently offer a webhook feature. However, you can use tools like Make or Zapier. These platforms allow you to create a webhook URL that will wait to receive information from Tapsite.ai. Once the data is received, it can then be sent to Manychat.

Please see the article below for a step-by-step guide on how to integrate Make with Manychat:
https://apps.make.com/manychat

Make, for example, offers a generous number of free operations per month.