AX-2012 R2 Letter of Credit

One of my client requirement is to track standard Letter of Credit and Purchase orders related to this.

1- How in AX-2012 R2 I can track these Purchase orders for LC

2- How I active LC option in GL Parameter form, I checked there is no such option available

3- Bank document check box in the Configuration form (kindly provide the path where this option available)

Looking forward for kind reply.

Regards