Obviously a telegram scammer do not entertain this people block and report them in telegram.
I also had this kind of invitation but I refused it as soon as I heard his scheme. He even offered me the same thing that he will be the one to make a deposit and all I have to do is just play it and he will let me win. He also said that he is one of the operators of that site and he wanted to bag some BTC and he needed that kind of help.
These guys are classic scammer I can't believe they still exist until today, hoping someone will fall into their trap. Most of the time they are finding newbies to trick.
I never respond about someone who i don't know PM me and offer something, any PMs i wouldn't ever to respond. I think people should do that because scammers will use a lot of ways to steal money from us. And something like what OP tell to us wouldn't harm anyone if people can ignore it. Glad for OP he is not easily believe to something like that.
the scammers will certainly do many ways to find people who are easy to get hooked and we must understand it. it's good indeed to forget and ignore things that are not clear, especially on offers that do not go in to what I think is potentially fraudulent. nowadays many methods are done by fraudsters, including sending PM or can also be via email but email will usually be more organized.
I think the best thing to do is just to like this post to share this message to everyone so that a lot of newbies in cryptocurrency could also be aware and could avoid this scam.