Usually how this works is wholesale customers log in to your store with a customer account in order to access the discounted prices.

Shopify has details on customer accounts here: https://help.shopify.com/manual/customers/customer-accounts

Inside our app, you'd then create a discount group with the tag 'wholesale', decide the discount to give them then add that 'wholesale' tag to your wholesale customer's accounts. When they log in to your website, they'll then see the discounted prices.