Just a note: there is not an ICCID until activation is complete. The activation process is where the the e-SIM is configured and the information is downloaded to your watch, this is when you will be able to find an ICCID.
Yes a common error is to confuse the ICCID for IMEI, hey I do it at least once a week. The ICCID is what in previous devices would have been called a nano-SIM, micro-SIM or SIM with the ICCID number printed on the SIM card.
Dave