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