How to add setup parameters to a new shell input in the Splunk Add-on Builder?

[hettervik]

On the page "Configure data collection using a REST API call" there is a section about adding setup parameters. However, on the shell input page "Configure data collection using a shell command" there is no such section. There is a section about adding input parameters, but it's not the same. The reason I'm asking is because I'm trying to add setup parameterts to a shell input, and I just get error messages in the final validation page, no matter what I do.

Should it be the same syntax as for REST-inputs, or is it different for shell inputs?

See attached screenshot of what I'm trying to do. I've already tried the following versions of the parameter syntax, but I get the same error messages for all of them,  and yes, I've added values to the parameters (in the Add-on Setup Parameters tab).

${__settings__.additional_parameters.my_parameter}
${additional_parameters.my_parameter}
${my_parameter}

Also, I get it to work if I switch to input parameters instead, but in this case I want to use setup parameters, as I'm planning to re-use the parameters in several inputs.