You need to follow up below commands in order to convert files to .crt/.key easily.
Prerequisites:
Extract .crt and .key file from .pfx file in Minutes
Why Manual Management of SSL\TLS Certs Destroys Security
For something so important, if you look around, you will find that the means and methods of managing SSL and TLS certificates are stuck somewhere in the past. Despite being the backbone of cybersecurity, IT folks often recount an alarming dependence on ad-hoc, manual, or semi-automated approaches to addressing this problem.
The range of tasks involved with certificate management is greater than one might assume at first glance. For example, someone has to purchase certificates and renew them when they expire, time-consuming activity in and of itself. Then, there’s the actual deployment of certificates, etc.