Yes - in theory you can use SOAP envelopes in a RESTfull API (and that because SOAP is a protocol and REST is architectural definition without claiming the use of any specific protocol)... However in our reality the actual templates to create RESTfull API (for instance in VS) does not support it and for that you will have to do a lot of hand-writing to fill the gaps...
In any case it is not needed (and advised) to use SOAP with REST, as both have different purposes...
To make the right decision you should first understand the differences and usage of both...
Understanding SOAP and REST Basics And Differences[
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