curl --request POST \
  --url https://ah-api.merge.dev/api/v1/registered-users/{registered_user_id}/link-token \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "connector": "slack"
}'

{
  "link_token": "lt_abc123xyz789"
}