Enabling Postcode field for shipping and billing for Countries not enabled

Hello,

I would like to enable postcode entry for shipping zones on the website I am working. I understand through another post that postcodes for Nigeria State or Cities have not been automated.

I have tried to checkout field editor plugins to achieve this objective but I have not been successful. I do see that the postcode field is enabled while the checkout form is loading but fields disappear on complete load.

Kindly assist.

Thank you.

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