I don't think this is quite correct. Most lte phones will have volte but I found this "What are the differences between LTE and VOLTE? 1) LTE only supports data. This technology is purely data-based, which means that it is not designed to handle calls and other types of services. VOLTE, on the other hand, can be used for both calls and data"
For simplicity, LTE (Long Term Evolution) and LTE-A (Long Term Evolution - Advanced) are generally marketed as 4G to simplify things for the public.
The same with 5G, there's actually 3 types, 5G Sub6, 5G SA and 5G mmWave. Technically, 5G is the public facing marketing name, as 5G is actually under the umbrella name of NR (New Radio)
But for the original question, and as @Troubadour pointed out, you should be fine if the device has VoLTE.
