issuedAt

@SerialName(value = "iat")
@Serializable(with = InstantLongSerializer::class)
val issuedAt: Instant? = null(source)

The "iat" (issued at) claim has the same meaning and processing rules as the "iat" claim defined in Section 4.1.6 of RFC7519, except that the value is a NumericDate, as defined in Section 2 of this specification. The Claim Key 6 is used to identify this claim.