Instead of "group" or "channel" - the name of your community from the address bar. After the = sign, indicate in Latin letters the source where you place this link, for example, "advertisement".
So the finished link might look like this:
https://vk.me/club192634149?ref=advertisement
https://t.me/smartbotpro?start=advertisement
After clicking on the link, the "reklama" parameter will be saved as a person's user variable, and in the future, the parameter can be used for conditions in the script.
Now you know how to create and apply referral links in Smartbot Pro!