Task: Create a new user in Notion based on the signup form submission

n8n workflow JSON:
{"nodes":[{"name":"Extract Name and Email","type":"n8n-nodes-base.set","position":[950,130],"parameters":{"values":{"string":[{"name":"Name","value":"={{$json[\"body\"][\"name\"]}}"},{"name":"Email","value":"={{$json[\"body\"][\"email\"]}}"}],"boolean":[]},"options":{},"keepOnlySet":true},"typeVersion":1},{"name":"Sign Up","type":"n8n-nodes-base.webhook","notes":"Example Input Data: {\"name\":\"John Doe\",\"email\":\"doe.j@northeastern.edu\"}","position":[720,130],"webhookId":"6d60a1b4-6706-4f21-a5fb-bace13c24b53","parameters":{"path":"sign-up","options":{"responseData":""},"httpMethod":"POST","authentication":"basicAuth"},"credentials":{"httpBasicAuth":{"id":"11","name":"Oasis Basic Auth Creds"}},"notesInFlow":true,"typeVersion":1},{"name":"If user exists","type":"n8n-nodes-base.if","position":[1560,150],"parameters":{"conditions":{"string":[],"boolean":[{"value1":"={{Object.keys($json).includes(\"id\") }}","value2":true}]}},"executeOnce":false,"typeVersion":1,"alwaysOutputData":false},{"name":"Create User","type":"n8n-nodes-base.notion","position":[1750,240],"parameters":{"resource":"databasePage","databaseId":"27a30c5b-c418-4200-8f48-d7fb7b043fbe","propertiesUi":{"propertyValues":[{"key":"Name|title","title":"={{$json[\"Name\"]}}"},{"key":"Email|email","emailValue":"={{$json[\"Email\"]}}"}]}},"credentials":{"notionApi":{"id":"3","name":"Oasis Hub Production"}},"typeVersion":1},{"name":"Query for User","type":"n8n-nodes-base.notion","position":[1150,230],"parameters":{"options":{"filter":{"singleCondition":{"key":"Email|email","condition":"equals","emailValue":"={{$json[\"Email\"]}}"}}},"resource":"databasePage","operation":"getAll","databaseId":"27a30c5b-c418-4200-8f48-d7fb7b043fbe"},"credentials":{"notionApi":{"id":"3","name":"Oasis Hub Production"}},"executeOnce":false,"typeVersion":1,"alwaysOutputData":true},{"name":"Query Current Semester","type":"n8n-nodes-base.notion","position":[2180,-30],"parameters":{"options":{"sort":{"sortValue":[{"key":"created_time","direction":"descending","timestamp":true}]},"filter":{"singleCondition":{"key":"Is Current?|checkbox","condition":"equals","checkboxValue":true}}},"resource":"databasePage","operation":"getAll","returnAll":true,"databaseId":"2003319a-bc73-423a-9378-01999b4884fb"},"credentials":{"notionApi":{"id":"3","name":"Oasis Hub Production"}},"typeVersion":1},{"name":"Select Semester ID","type":"n8n-nodes-base.set","position":[2370,-30],"parameters":{"values":{"number":[],"string":[{"name":"currentSemesterID","value":"={{$json[\"id\"]}}"}]},"options":{},"keepOnlySet":true},"typeVersion":1},{"name":"Update Semester for User","type":"n8n-nodes-base.notion","position":[3050,110],"parameters":{"pageId":"={{$json[\"id\"]}}","resource":"databasePage","operation":"update","propertiesUi":{"propertyValues":[{"key":"Semesters|relation","relationValue":["={{$json[\"allSemesterIDs\"].join(',')}}"]}]}},"credentials":{"notionApi":{"id":"3","name":"Oasis Hub Production"}},"typeVersion":1},{"name":"Merge Semester ID","type":"n8n-nodes-base.merge","position":[2590,110],"parameters":{"mode":"multiplex"},"typeVersion":1},{"name":"Concatenate Semester IDs","type":"n8n-nodes-base.function","position":[2820,110],"parameters":{"functionCode":"for (item of items) {\n  // Get the current semester ID\n  const currentSemesterID = item.json[\"currentSemesterID\"]\n  let allSemesterIDs = [currentSemesterID];\n\n  // Add semesters that the user is already associated with\n  if (item.json[\"Semesters\"]?.length > 0) {\n    allSemesterIDs = allSemesterIDs.concat(item.json[\"Semesters\"].filter(semesterID => semesterID !== currentSemesterID));\n  }\n\n  // Set allSemesterIDs which is used to update the relation\n  item.json[\"allSemesterIDs\"] = allSemesterIDs\n}\n\nreturn items;\n"},"typeVersion":1},{"name":"Merge","type":"n8n-nodes-base.merge","position":[1340,150],"parameters":{"mode":"mergeByKey","propertyName1":"Email","propertyName2":"Email"},"typeVersion":1},{"name":"Query User","type":"n8n-nodes-base.notion","position":[1950,130],"parameters":{"options":{"filter":{"singleCondition":{"key":"Email|email","condition":"equals","emailValue":"={{$json[\"Email\"]}}"}}},"resource":"databasePage","operation":"getAll","returnAll":true,"databaseId":"27a30c5b-c418-4200-8f48-d7fb7b043fbe"},"credentials":{"notionApi":{"id":"3","name":"Oasis Hub Production"}},"typeVersion":1,"alwaysOutputData":true}],"connections":{"Merge":{"main":[[{"node":"If user exists","type":"main","index":0}]]},"Sign Up":{"main":[[{"node":"Extract Name and Email","type":"main","index":0}]]},"Query User":{"main":[[{"node":"Query Current Semester","type":"main","index":0},{"node":"Merge Semester ID","type":"main","index":1}]]},"Create User":{"main":[[{"node":"Query User","type":"main","index":0}]]},"If user exists":{"main":[[{"node":"Query User","type":"main","index":0}],[{"node":"Create User","type":"main","index":0}]]},"Query for User":{"main":[[{"node":"Merge","type":"main","index":1}]]},"Merge Semester ID":{"main":[[{"node":"Concatenate Semester IDs","type":"main","index":0}]]},"Select Semester ID":{"main":[[{"node":"Merge Semester ID","type":"main","index":0}]]},"Extract Name and Email":{"main":[[{"node":"Merge","type":"main","index":0},{"node":"Query for User","type":"main","index":0}]]},"Query Current Semester":{"main":[[{"node":"Select Semester ID","type":"main","index":0}]]},"Concatenate Semester IDs":{"main":[[{"node":"Update Semester for User","type":"main","index":0}]]}}}