Applying with no support letter or rescheduling the appointment?

Hi! So tomorrow I have the appointment for my TN visa. My employer could not get the letter ready and signed on time. It was an HR/admin issue. The problem is that my appointment is still coming up.

Do you recommend I try to reschedule/cancel (the 24hr limit has passed) or should I go to the interview with only the job offer. It is rather comprehensive, including start/end dates and a thorough job description; however, it’s not a TN support letter, so I feel like I risk being denied on the spot.

If I reschedule my concern is not making it by my start date, but I could also just try my luck and if it gets denied, wouldn’t it be a similar process? I’d appreciate any advice

Update: It was approved! I went to my interview appointment at the consulate. From the start, at the entrance, they did tell me my letter was missing, but did not turn me back. I eventually got to the interview, missing letter and all. I had to thoroughly describe my job and responsibilities. Even if I got it, I wouldn’t advice being underprepared. It’s really stressful and I still think it was quite risky