Associate VPS with OVH Domain

I'm new to OVH.
I bought a VPS Starter.
Later I also bought a domain **my-domain.ovh**; if I had done it first, I would have immediately associated a new VPS. Now I want to associate the VPS that I had already bought.
I have already given the hostname **srv.my-domain.ovh** to the VPS.
What should I do?

I will install BIND on the server and it will only serve as my personal name server to address other servers which I will then activate on OVH.

Thanks in advance.