Serve PHP Website on another machine when using Mail in a box

I have a domain name - I gave my box name -
I am using digitalocean and my nameservers are pointing to,
I am using A record for to point to this machine where i installed mail in a box.
Problem is, I want to serve a wordpress website on from another machine, which is already setup.
Can anyone please help me here and suggest me how i can do that…

For the domain in question, just make a new A recorder pointing to the server hosting the site.