I have a problem struggling with it in the current time, i am testing the checkout section, enter the data in their fields, but in the dropdown of region/country, doesn’t offer any further options to select, that mean i cannot select where the country or region that the product should shipping to.
This issue sounds like it’s due to Shopify Markets – can you check if you have access to this feature on your store?
If you do, you can navigate to Settings > Markets to check if the other regions on your store has been activated within the Markets settings of your store. If a region you wish to sell to isn’t currently active on your store, you can click Manage > Activate market for the market that wish to activate. This should then also activate the region within the dropdown options on your checkout page.
As you mentioned that you’re currently testing your checkout, I thought I’d leave our help guide here on testing the Shopify Payments gateway for your reference. If you’re not using Shopify Payments, other payment processor should also have their own test mode too that you can enable. This will allow you to simulate a successful transaction on your store to make sure your checkout is functioning as intended.