If it’s not in any settings menu, then you can try this:
Dial *#*#4636#*#*
… this will bring up a “Testing” menu.
Choose “Phone 1 information” for SIM 1 or “Phone 2 information” for SIM 2 and then scroll down to the “SMSC:” field.
Then …
If it’s not in any settings menu, then you can try this:
Dial *#*#4636#*#*
… this will bring up a “Testing” menu.
Choose “Phone 1 information” for SIM 1 or “Phone 2 information” for SIM 2 and then scroll down to the “SMSC:” field.
Then …