Is it too late to do workers comp? And how to file it?

So I got injured at work a less than a few weeks ago and during that time I didn’t know that I had a sprained knee because it was both of my legs at the time until I went back to work that day when it got worse then I went to a hospital later on because I went to my local clinic that told me to get an ultrasound done at the hospital but after that i ended up trying to report it to my boss again who is hard to reach I even said that my leg been bothering me the day after which is I did report to him but should have said that it started at work and asked him if it was too late to my gm manager who at first was going to fill out paperwork for me to get workers comp because I did notify other managers that closed that day but somehow they didn’t remember that i told them and my boss denied me and said that i can’t get workers comp because i didn’t notify anyone even though i did and i notified the hospital when i was there which i believe they have the documents on it from that day but is it too late to do workers comp? I also texted my boss explaining what happened but he didn’t even respond to it which is what i have an issue with because he doesn’t respond at certain times especially at night even in the day time. I also have a witness i told also who knows that i got injured at work. And have another witness and a text that was saying that my legs were hurting that day.

But is there a way to file workers comp or is it too late?