Task: Publish a post to a publication on Medium

n8n workflow JSON:
{"id":"7","name":"Publish post to a publication","nodes":[{"name":"On clicking 'execute'","type":"n8n-nodes-base.manualTrigger","position":[600,300],"parameters":{},"typeVersion":1},{"name":"Medium","type":"n8n-nodes-base.medium","position":[800,300],"parameters":{"title":"","content":"","publication":true,"contentFormat":"","publicationId":"","additionalFields":{}},"credentials":{"mediumApi":"medium"},"typeVersion":1}],"active":false,"settings":{},"connections":{"On clicking 'execute'":{"main":[[{"node":"Medium","type":"main","index":0}]]}}}