This can be done easily using Facebook’s internal QR Code function.
Just go to your company’s page and click on Edit Page Info. Scroll down a bit and you will see the QR Code.
Facebook QR Code for a Page
Click on the QR Code and it will popup in a new tab or download it. The URL in the QR Code looks something like this: https://facebook.com/qr/<QR_ID> and by scanning the code the encoded URL deep links you in the Facebook App on both IOS and Android devices or in the browser as fallback.
Designer Facebook QR Code
As you can see from the previous screenshot this is a simple black & white QR Code with the Facebook logo in it. To create a designer QR Code with your own colours, forms and frames you can use a designer QR Code Generator by pasting the URL of the QR Code.
Designer QR Code Templates
In the following post I wrote a more detailed description on how to create a deep linking QR Code with your own design:
https://blog.qrd.by/2021/02/19/create-facebook-qr-code-with-a-deep-link/