Step 1: Go to below URL to create an account in ups.
Using Sign-up link to create an account.
Step 2: Once creating the account going to login and download API under Developer APIs
Step 3: Once download the API configure using User Id, Password and Access Key. How to get Access key means, click on the Request an access key link to give all personal account valid details and card information to get access key from UPI.
Step 4: Once get the access key going configure into magento 2.x store.
Go to store->configuration-> under sales menu -> shipping methods
If your store in development, usingtest mode to configure and test the UPS API