Which HTTP method to use for this client request?

I am developing a REST web service in Java which on clients' request processes the request body and gives the output to the client. The request body sent by the client consists of a GO(programing language) program which the server executes(runs) on the server machine and returns the standard output of the program back to the client. Now since the request body contains some text(program), I cannot use HTTP GET method to do that. I can use PUT or POST, but I have learnt that they(PUT and POST) are generally used for updating/creating a resource. Since, I am not creating any resource here, is it conceptually correct to use PUT or POST. If not, which is the HTTP method that I need to use?

Looking at the problem you are solving and comparing to an existing production solution , I suggest that you can use POST in your scenario.

• Reasoning - Example Production code solving similar problem:-

Assuming that the problem you are trying to solve is this:-
Clients submit code in Go programming language, Your server compiles it, runs it and then gives the output. Assuming also that, it is somewhat similar to many online coding websites like hackerEarth, their API documentation page and the sample python code provided show that we can use HTTP:POST to submit code to the server for its processing.

• Reasoning - RFC for HTTP POST, PUT :-

POST is designed to allow a uniform method to cover the following functions:
Providing a block of data, such as the result of submitting a
form, to a data-handling process;

The PUT method requests that the enclosed entity be stored under the supplied Request-URI. If the Request-URI refers to an already existing resource, the enclosed entity SHOULD be considered as a modified version of the one residing on the origin server.

• Referring to the above statements, we can conclude that in the context of this problem which you are solving, you are requesting the server to do some data-handling for the enclosed entity, so you can use POST.