Task: Verify an email recipient with uProc

n8n workflow JSON:
{"id":"103","name":"verify email","nodes":[{"name":"On clicking 'execute'","type":"n8n-nodes-base.manualTrigger","position":[440,510],"parameters":{},"typeVersion":1},{"name":"Create Email Item","type":"n8n-nodes-base.functionItem","position":[640,510],"parameters":{"functionCode":"item.email = \"mcolomer@gmail.com\";\nreturn item;"},"typeVersion":1},{"name":"Check Email Exists","type":"n8n-nodes-base.uproc","position":[850,510],"parameters":{"tool":"checkEmailExists","email":"={{$node[\"Create Email Item\"].json[\"email\"]}}","additionalOptions":{}},"credentials":{"uprocApi":"miquel-uproc"},"typeVersion":1},{"name":"Email Exists?","type":"n8n-nodes-base.if","position":[1050,510],"parameters":{"conditions":{"string":[{"value1":"={{$node[\"Check Email Exists\"].json[\"message\"][\"response\"]}}","value2":"deliverable"}]}},"typeVersion":1}],"active":false,"settings":{},"connections":{"Create Email Item":{"main":[[{"node":"Check Email Exists","type":"main","index":0}]]},"Check Email Exists":{"main":[[{"node":"Email Exists?","type":"main","index":0}]]},"On clicking 'execute'":{"main":[[{"node":"Create Email Item","type":"main","index":0}]]}}}