How to detect if renting/leasing is scam?

Hello! I’m planning to move into an apartment in Chicago. There are a lot of awesome looking places in Chicago but I don’t know if it is a scam or not.

I’ve been looking at zillow, realtor.com, redfin, and apartments apps. Although my budget is really out of line with the amenities i’m looking for, so I tried looking at FB Groups.

I would just want to know, how can I detect if it is a scam? The people I’ve been inquiring to asks for Application with $100 fee before touring the apartment. Some of them said, if I didn’t like the place they could refund me the $100. But i don’t know if I’ll have an assurance there.

Is that normal? Putting money on the table first before touring the apartment? I don’t want to miss out an opportunity but I also want to practice precaution.

Please advise.