https://help.shopify.com/en/manual/shipping/setting-up-and-managing-your-shipping/enabling-shipping-carriers/ups
Step 1: Register for an account with UPS
Step 2: Get your UPS account number
Step 3: Verify your address
Step 4: Verify your invoice
Step 5: Connect your UPS account
Step 6: Test your carrier-calculated shipping rates
Step 7: Set up carrier-calculated shipping rates