In order to become a massage therapist in the US, you will need to become a licensed massage therapist at least in most states. Only a few states still do not have licensing requirements at this time like Minnesota, Wyoming, Vermont. California has voluntary certification/licensing but is working on state licensing. (April 2022).
Each state has different education requirements, school requirements and application processes for becoming a massage therapist. These laws and regulations are also subject to change.
The links in the chart go to pages on this website that provide a more comprehesive but not exclusive information on massage licensing in each state. There are exceptions, differences in education requirements, differerences in licensing renewal and many other things that vary but state that you will need to read each states complete licensing rules and laws.