It starts but after a minute or two it cuts off?

Hello,

If for some reason the timing marks are off you could have similar issues.
Since the belt was replaced you want to make sure that is is aligned properly. It can be an issue with the timing belt tensioner.

https://www.2carpros.com/articles/how-a-timing-belt-works

When the engine runs, does it run smooth or rough?

Is the check engine light illuminated? If the issue due to a sensor the engine light will get triggered.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I have attached the timing belt replacement procedure including the marking for your reference.

Please let me know of any questions.
Thank you.