With the above information being considered, it's important to make sure that you meet the eligibility requirements to be able to use a Shopify Card Reader. Can you share with me what country you operate your business out of?
I have an example of the webpage where you would buy your card reader from here. This is the Canadian site, and I'm just using it as an example here. Below I have a list of all of the countries that have a supported, official Shopify Hardare Store:
Check out that list and see if the country you operate your business out of is supported there. For those folks that don't have a supported store, or can't use Shopify Payments, you can set up an external reader and processor that integrates with your store instead. We have a list of officially supported readers at this page here, along with a longer list of all supported POS hardware at this link.
Hopefully you find this information helpful! Feel free to follow up with me here letting me know where you operate your business out of, along with a URL to your shop, and I'd be happy to provide you with some more tailored information.
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