adria14265 (i lost the simcard but never reported it, i still have access to the account)
How long ago did you lose the SIM?
If that SIM/number has not been used for six months or more it will have been deactivated and the number sent for recycling.
Does the number still appear, top left, on the dashboard for that account? If it does then it is probably still active and you can SIM Swap as advised above.