Configure an apex domain on Netlify not working with Hostinger Domain

We have a domain nexsync.org on Hostinger where we buy all my domains but all attempts to link my netlify project nexsync.netlify.app to nexsync.org has failed, except when we replace the DNS on Hostinger with that of Netlify.

Though this 2nd approach worked, the email server and all that was initially configured on Hostinger failed to work with Netlify, so we had to reverse.
Please, how do I resolve this?

Hoping to hear from you soon.

If you don’t want to use Netlify DNS you can configure the domain using external DNS.

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