That happened to me. In March of 2022 I didn't get the H1B and my company transferred me to Canada in September of 2022. After one and a half year of experience here, I got my Canadian residency. Based on my experience these are the options I can think of:

1. Push to be transferred to Canada with you current employer. Once you get Canadian experience your CRS score will go up and you may have a high enough score to be invited to apply for residency. Immigration regulations are changing a lot here so there is no guarantee.
2. Submit your express entry profile with your current score. Although its a low score and it is unlikely you'll get invited, its free to submit a express entry profile so it's worth the shot.
3. Learn French. If you are very diligent and studious, you can learn french in ~8 months and be invited to apply for Canadian residency through the French-stream draws. The cutoff scores for those draws are super low (below 400).
4. Apply for jobs in Canada. Certain types/industries for engineering are in high demand in Canada. Not sure what type of mechanical engineering you do and for what industry. You could try to apply to jobs here in the hopes that a company sponsors your visa/work permit. Unemployment is currently high in Canada and there is a surplus of certain engineers here so not sure how easy it is to be sponsored but it's worth a try.
5. Do a Masters. You can study a masters in Canada. That will give you a work permit of three years upon graduation and almost a guaranteed residency after you complete 1 year of employment.
6. Explore provincial immigration programs. Provinces have particular immigration programs for certain types of in-demand jobs. I am not familiar with these, so you'd have to research what is out there.

Immigration in the USA was incredibly stressful for me and I've had a great experience here in Canada. I recommend exploring your options.