My domain provider's contol panel only provides an interface for nameservers.

There are 5 fields Nameserver 1 ... Nameserver 5.

Currently those fields are pointed to the NS1.XYZ.TLD ... NS5.XYZ.TLD of the web host (where the actual content of the website is).

I tried to swap Nameserver 5 text from NS5.XYZ.TLD to zoho-verification=zb######.zmverify.zoho.com (##### being the number displayed in my Zoho screen....the result below appears:

Invalid nameserver given zoho-verification=zb#####.zmverify.zoho.com

I then tried to follow  CNAME Method

so I put ZMVERIFY.ZOHO.COM in Nameserver 5. Saved, went into Zoho, nothing changed

HTML method I cannot imagine doing, I cannot see where to set it up on my domain host