Returns a JWT token suitable for APNs.

Options

• :jwk - JWK from PEM-encoded token signing key downloaded from developer.apple.com
• :kid - The 10-character Key ID you obtained from your developer account; see Get a key identifier.
• :iss - The issuer key, the value for which is the 10-character Team ID you use for developing your company’s apps. Obtain this value from your developer account.
• :cache - an ETS table name to be used as cache. For example: :ets.new(:your_name, [:named_table, :public, read_concurrency: true])

Please see Obtain an encryption key and key ID from Apple for more details.