On the right-hand side of the link you provide is a section called:
This will take you here - https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/virtual-chassis-qfx-series-cli.html
Which was step-by-step how to config via various methods. Since yours is a 2-member VC (does not matter the model or product type) be sure to set no-split-dection for best operation.