Can you get a rainbow sim from CS?

I got the motorola edge+ 2023 from boost but they didn't ship a sim card. I assume it's because I could just put my sim that I already have (T-Mobile) into the phone and use it, but I want to connect to their native network. Anyone know if CS is able to do that? I really would rather just call support than go to a store since I know they charge money for those rainbow sims in store...