Belvo employs basic authentication using your secret keys. Just use your secretId as the username and secretPassword as the password. For example:
curl \
-u =BASE64-SECRET_ID=:=BASE64-SECRET_PASSWORD=
https://sandbox.belvo.com/api/
curl \
-u =BASE64-PAYMENTS_SECRET_ID=:=BASE64-PAYMENTS_SECRET_PASSWORD=
https://api.belvo.com/payments/
To generate your Aggregation and Enrichment API keys, see generate aggregation and enrichment API keys.
To generate your Payment Inititation API keys, see generate payment API keys.