Company red flag

I dont know but the digital marketing company i got called for a interview is very sketchy, i went for a interview they made me write a essay for like a hour said we will message you in evening i kept on asking for a response they delayed it to like next day. Then they say to come on sunday for a 7 day unpaid trial

(I knew that they would ask for a 7 day unpaid trial as they asked in the job posting to look how much i improve and learn from them as i am a fresher)

But i think they might make me work for a week and even if i do my best they might reject me for free labor lmao

This company has so many vacancy post for employees every 3 months and cant even find a linkedin profile and had a hard time finding them in google maps not much digital footprint only facebook page and they are in merojob and kumari job.

TLDR: Company i applied for might be using me for illegal free labor.