Hi if you dont use liff.js you need to add userID append liffURL. Use case: Customer chat with bot in web hook you can get userContext e.g userId and response to user with liffurl+query string e.g
Sorry for my bad english hope you can understand!
Thank you, I known that way , but I mean when user click Liff URL on LINE app, LINE server can set the user ID in request and then I can get the user ID in my endpoint URL (I'm using Laravel). NOT USING Javascript (https://static.line-scdn.net/liff/edge/2.1/sdk.js), because we have a problem by that way. Hope you can understand.
You can use LIFF API method liff.getProfile() for get userId see detail from link below https://developers.line.biz/en/reference/liff/