In your credentials file, you must provide your Linode Personal Access Token
This provider does not recognize any special metadata fields unique to Linode.
Linode does not allow all TTLs, but only a specific subset of TTLs. The following TTLs are supported (source):
The provider will automatically round up your TTL to one of these values. For example, 600 seconds would become 3600 seconds, but 300 seconds would stay 300 seconds.