How to specify request headers for a post method

You can do the following in the @Operation annotation over your method

@Operation(description = "This is my api",
    parameters = {
    @Parameter(in = ParameterIn.HEADER,
        name = "X-Version",
        description = "The API Version",
        required = true,
        schema = @Schema(type = "string"))}
)

You can also specify more details to the @Parameter or @Schema annotations if required.

Checkout the last section of Operation documentation

The above annotation showed up this way in my app's documentation