Put a bought template of an e-commerce website and don't know hot to put it in Figma

Hi, hope y’all doing fine,
I have a school project on Figma and the dead line is today at 23:59, I had to design an e-commerce template website but didn’t know anything about Figma so I bought a template that I found on themeforest. I tried to open the file that was sent to me but couldn’t open it (I’m using a 2018 MacBook), I tried to open the file on Figma, but I can’t open a .fig document in Figma. Can please someone help me to put the template on my Figma account please ?
Thank you in advance. Have a good night.