The Rainforest API uses API keys with Bearer Authentication.
API keys are prefixed with apikey_ in production and sbx_apikey_ in sandbox.
Provide the API key in the Authorization header with the Bearer prefix.
curl --request POST \
--url http://api.sandbox.rainforestpay.com/v1/payin_configs \
--header 'Accept: application/json' \
--header 'Authorization: Bearer {{your_apikey}} ' \
--header 'Content-Type: application/json'
--data '...'