You can actually get a Tracfone nano-sim, but it’s not as easy as that to add it to a dual sim iPhone. With the iPhone, one sim is physical and one is virtual (esim). If you have a SIM card currently, you’ll have to have your carrier make the switch and I’ve heard they’re sometimes reluctant to do so (although it’s not technically difficult).
If your primary is already on esim (which is likely if you bought your phone directly from Apple), then adding your hobby phone to your main phone is as easy as buying a nano-sim from Tracfone.
If your primary is on a sim, then you can easily add another carrier to the esim, with Google Fi being the easiest (and Google Fi, unlike Voice, pings as an actual number for providers who make a distinction).
Finally, a second carrier can only be activated if your phone is unlocked. If you bought your phone from a carrier like Verizon or AT&T, it’ll be locked to that network. They’ll unlock it but only if you don’t owe them any money on the device or account.
My personal experience with this has been with activating the esim on my iPhone on Deutsche Telkom when in Europe. When both numbers are activated, you can easily turn each sim on/off in settings so you won’t receive calls or texts from your burner when you don’t want to. Unless someone is actively looking for the existence of the second sim and knows to look in cellular settings, it won’t appear in normal use of the phone.
