Task: Add contacts to SendGrid automatically

n8n workflow:
{"id":"209","name":"Create, update and get a contact using the SendGrid node","nodes":[{"name":"On clicking 'execute'","type":"n8n-nodes-base.manualTrigger","position":[270,300],"parameters":{},"typeVersion":1},{"name":"SendGrid","type":"n8n-nodes-base.sendGrid","position":[470,300],"parameters":{"email":"","resource":"contact","additionalFields":{"firstName":""}},"credentials":{"sendGridApi":"SendGrid Credentials"},"typeVersion":1},{"name":"SendGrid1","type":"n8n-nodes-base.sendGrid","position":[670,300],"parameters":{"email":"={{$node[\"SendGrid\"].parameter[\"email\"]}}","resource":"contact","additionalFields":{"lastName":""}},"credentials":{"sendGridApi":"SendGrid Credentials"},"typeVersion":1},{"name":"SendGrid2","type":"n8n-nodes-base.sendGrid","position":[870,300],"parameters":{"by":"email","email":"={{$node[\"SendGrid\"].parameter[\"email\"]}}","resource":"contact","operation":"get"},"credentials":{"sendGridApi":"SendGrid Credentials"},"typeVersion":1}],"active":false,"settings":{},"connections":{"SendGrid":{"main":[[{"node":"SendGrid1","type":"main","index":0}]]},"SendGrid1":{"main":[[{"node":"SendGrid2","type":"main","index":0}]]},"On clicking 'execute'":{"main":[[{"node":"SendGrid","type":"main","index":0}]]}}}