Doing Page customization on Supplier Portal in production instance

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Hi All,

We are looking for inputs on how we can do the page customizations for supplier portal in production instance?
In test instance, we can access the supplier portal using test account and do the customization, however in production instance, we will not have any test account to access the supplier portal. We are looking for methods on how we can do the customization? Are there any ways to export - import the customizations? If any of you have done it in past, what methods were used?

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