Unit REST API

Sign up for a Unit sandbox account at Sandbox and choose Custom Build. In the Unit Dashboard, go to Developer → API Tokens to create an org-level token with the scopes you need; the docs say org API tokens can also be created programmatically or through the Dashboard. Use the live dashboard at app.unit.co for production tokens after your live environment is enabled.

First create or identify a Unit customer in your program. Then use an org token with the customer-token-write scope to call the Customer Token API described at Customer API Tokens. For sensitive scopes, first create a verification challenge at POST /customers/:customerId/token/verification, collect the OTP from the customer, then create the customer token at POST /customers/:customerId/token with verificationToken and verificationCode. In sandbox, the docs say to use passcode 000001 for this verification flow.