I want to transfer slack message to notion database item with using slack emoji, so
I checked several triggers of slack app.
I found ‘New Event’ module, but this is using webhoook but slack does not recommend using outgoing webhooks. (Legacy custom integrations outgoing webhooks | Slack)
Is there a way to do?
I found the way with using Zapier…(https://zapier.com/apps/notion/integrations/slack/602096/add-items-to-databases-in-notion-with-new-slack-reactions)
Hi 
I believe what Zapier use in the mentioned Zap is the very same Make incorporated in the “New Event” module.
It is Slack Events API not classic Slack webhooks which might not be recommended anymore.
You could then use the mentioned module set to watch the reactions and filter them according to your need in order to get the data you need for the Notion module(s).
In case you would want to do it without the mentioned instant trigger module, you could use the “List Replies” module but it might get very complicated as the module-specific “Channel ID” and message “timestamp” you would need to get by constantly listing/watching all messages in specific channels.
I would not recommend building such a scenario flow as it might consume a lot of operations and would not work instantly as with the “New Event” module.
TLDR - It is safe to use the “New Event” module to watch reactions (emojis) as it incorporates Slack Events API
Cheerio