I'm confused about how to point a subdomain from a domain I bought on namecheap to a Wordpress droplet on Digital Ocean.

I found https://www.digitalocean.com/community/tutorials/how-to-set-up-a-host-name-with-digitalocean and https://www.digitalocean.com/community/tutorials/how-to-set-up-and-test-dns-subdomains-with-digitalocean-s-dns-panel, but do I actually need to change my domain server if I want my original domain to continue being hosted where it is?

I just want the subdomain pointed to the Digital Ocean droplet, not the original domain.