I have been reading across multiple posts for the correct way to set up my new phone for international travel. I will be in South Africa for 2.5 weeks and want to use my phone's dual sim capabilities in the best way possible.

I have Verizon psim as my primary carrier/number. I have 5G Play More plan
I have TMobile esim as secondary. I have the Magenta +55 plan. I have Digits app installed

This is my first time to have a phone that supports dual sims. I am confused about how best to set it up for optimal international use and charges. I'm confused about whether or not I still need the Digits app now that my phone has 2 sims. Previously I had two separate phones, one for each line.

I appreciate any help forthcoming. I have tried to do the research myself but end up confused, especially as many articles are using iPhones and I have the Samsung G24 Ultra android system. Thank you in advance! Deb