How do I Insert Smart Card Dummy E7450?

Hello

I have recently got a used Dell E7450, very happy with it !

It came with the smart card slot open as pictured and I bought PN YKG9J to insert it (in the idea less dust gets inside). It doesn't seem to fit easily like the SD dummy and I don't want to force it.

Please advise how to insert it. Do I have to take apart the laptop ?

Thanks