the procedure would be:
1. Deploy NSX manager OVA
2. Add Compute Manager
3. Deploy 2 more NSX manager nodes.
4. Create Uplink Profiles (or use defaults)
5. Create NIOC _rofiles (or use defaults)
6. Create transport Zones
7. Create IP Pools for TEPs
8. create Transport Node profile(if you use vSphere esxi clusters)
9. Assign that profile to vSphere cluster to prep the hosts.
10. create segments
11. deploy Edge node VMs
12. create Routers.
etc..
Procedure might change depending on environment specifics. liek for example if you need to move your vmk interfaces to N-VDS as well.
If you are going to use Ansible, VMware guys have already automated this all for you, so you can just use examples from there: ansible-for-nsxt/examples at master · vmware/ansible-for-nsxt · GitHub
If your goal is to write all this manually using REST calls, then good luck, you will have to do a lot of API guide reading :smileyhappy: