Nighthawk R7000 as a Repeater with TP-Link AX-50

I recently purchased the TP-Link AX50 WiFi 6 Router which I have setup as a Primary Router. I would now like to use my existing Nighthawk R7000 as a Repeater.

I followed the instructions provided here: How do I enable the extender mode feature on my Nighthawk router? | Answer | NETGEAR Support but the instructions seem confusing to me and it did not work. Can someone guide me please.

For setting up the Nighthawk as the Repeater is there any configuration to be made on the Primary Router as well?