The Ubigi eSIM profile has unlimited validity period as it stays active as long as you top up your Ubigi account with a prepaid data plan at least once in 18 months.
This means that it is only after a period of 18 months of inactivity (i.e no prepaid data plan used at all) that the eSIM profile will automatically be terminated.
The period of 18 months is calculated from the date of your last consumption from the last prepaid data plan you used.