Quick question please respond before I leave...

I have a safety first car seat, yesterday I was at a thrift store and found a perfectly like new graco stroller. I have been in desperate need of one but can’t afford a brand new one so I bought the one pictured below. The car seat fits perfectly in it the only problem is it doesn’t click! I don’t know if I should take it back and just try to buy a new one eventually or give it a try?

What do you think? I’m gonna be leaving for the store where they don’t have carts so I was gonna use the stroller but not gonna if it isn’t safe.