help on wanting to use tello for 2FA texts for abroad

hi, i kindly ask someone knowledgeable to help a lost, clueless person like myself. i greatly appreciate it.

i will be abroad to south korea and canada for an extended time period. i want to receive texts for verification purposes with my us phone number.

i have an iphone 16 which can handle dual e-sim i believe. i know that i can get a local e-sim in the two locations i am going to.

what i need some help understanding is what do i need to do in my iphone settings to only receive texts (us phone number) with tello but have everything else go to the local e-sim.

also, for clarification, can i receive texts without a fee or does it have to be over wifi like phone calls?

i am worried i will accidentally have data usage on with tello, and i just have anxiety on how to navigate it properly without spending money i didn't intend to. i am sorry if this is such a dumb question. i just like double checking and knowing exactly what i should do. thank you!