get https://api.pay-link.eu/v1.0/Design//
Response
xxxxxxxxxx
apiSignature=`echo -n "" | openssl dgst -sha256 -hmac "INSTANCE_API_SECRET" -binary | openssl enc -base64`
curl --request GET "https://api.pay-link.eu/v1.0/Design/1/?instance=INSTANCE_NAME" --data-urlencode "ApiSignature=$apiSignature"